$60+ Cheap flights from San Francisco Bay Area to Illinois
This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/10. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ORD
Mar 7 — Mar 141
1 adult, Economy
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Find cheap flights from San Francisco Bay Area to Illinois with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
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Cheapest flights from San Francisco Bay Area to IllinoisExplore the most affordable flight options available from San Francisco Bay Area to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 5, 2026.
Explore the most affordable flight options available from San Francisco Bay Area to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 5, 2026.
This Kiwi.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/69:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/98:12 pm
STL
- SFO
1 stop25h 57m
Frontier
Deal found 2/1![Frontier logo]()
$151
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/109:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/168:12 pm
STL
- SFO
1 stop30h 16m
Frontier
Deal found 2/3![Frontier logo]()
$156
This Frontier deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/257:20 am
SFO
- STL
1 stop6h 33m
Frontier
Sat 2/282:51 pm
STL
- SFO
1 stop11h 37m
Frontier
Deal found 2/3![Frontier logo]()
$158
This Expedia deal was found by Cheapflights users on 2/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/268:48 am
SFO
- STL
1 stop26h 21m
Frontier
Mon 3/210:11 pm
STL
- SFO
1 stop22h 09m
Frontier
Deal found 2/5![Frontier logo]()
$168
This Kiwi.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/89:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/98:12 pm
STL
- SFO
1 stop25h 57m
Frontier
Deal found 2/1![Frontier logo]()
$170
This Kiwi.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/69:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Wed 3/1112:14 pm
STL
- SFO
1 stop21h 44m
Frontier
Deal found 2/1![Frontier logo]()
$177
This Priceline deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/286:15 am
SFO
- STL
1 stop5h 41m
Frontier
Wed 3/118:12 pm
STL
- SFO
1 stop6h 16m
Frontier
Deal found 2/4![Frontier logo]()
$179
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/109:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/238:12 pm
STL
- SFO
1 stop30h 16m
Frontier
Deal found 2/3![Frontier logo]()
$183
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/117:32 pm
SFO
- STL
1 stop21h 39m
Frontier
Mon 3/168:12 pm
STL
- SFO
1 stop30h 16m
Frontier
Deal found 2/3![Frontier logo]()
$185
This Frontier deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/1411:16 pm
SFO
- STL
1 stop12h 56m
Frontier
Mon 5/183:02 pm
STL
- SFO
1 stop9h 29m
Frontier
Deal found 2/2![Frontier logo]()
$190
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/109:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Sun 3/158:06 pm
STL
- SFO
2 stops51h 32m
Frontier
Deal found 2/3![Frontier logo]()
$191
This Alaska Airlines deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/197:00 am
OAK
- ORD
1 stop9h 46m
Alaska Airlines
Wed 5/209:00 am
ORD
- OAK
1 stop7h 32m
Alaska Airlines
Deal found 2/3![Alaska Airlines logo]()
$197
Best flights from San Francisco Bay Area to IllinoisDiscover carefully curated flight deals from San Francisco Bay Area to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 5, 2026.
Discover carefully curated flight deals from San Francisco Bay Area to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 5, 2026.
This Southwest deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/145:40 am
OAK
- MDW
Nonstop4h 00m
Southwest
Tue 3/179:00 pm
MDW
- OAK
Nonstop4h 40m
Southwest
Deal found 2/3![Southwest logo]()
$217
This Alaska Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/32:50 pm
SJC
- ORD
1 stop7h 09m
Alaska Airlines
Tue 3/108:20 am
ORD
- SJC
1 stop7h 53m
Alaska Airlines
Deal found 2/2![Alaska Airlines logo]()
$223
This Delta deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/2410:35 pm
SFO
- STL
1 stop7h 55m
Delta
Mon 4/271:45 pm
STL
- SFO
1 stop10h 40m
Delta
Deal found 2/4![Delta logo]()
$237
This United Airlines deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/3010:55 pm
SFO
- ORD
Nonstop4h 30m
United Airlines
Mon 5/410:45 pm
ORD
- SFO
Nonstop4h 50m
United Airlines
Deal found 2/4![United Airlines logo]()
$264
This Kiwi.com deal was found by Cheapflights users on 2/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/88:20 pm
SJC
- STL
1 stop12h 59m
Frontier
Wed 3/118:12 pm
STL
- SJC
2 stops23h 55m
Frontier
Deal found 2/5![Frontier logo]()
$269
This American Airlines deal was found by Cheapflights users on 2/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/86:00 am
SJC
- STL
1 stop9h 13m
American Airlines
Wed 3/115:12 am
STL
- SJC
1 stop7h 04m
American Airlines
Deal found 2/5![American Airlines logo]()
$290
This Kiwi.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/155:47 pm
SFO
- MLI
1 stop15h 42m
Multiple Airlines
Sun 4/1912:19 pm
MLI
- SFO
1 stop21h 59m
Multiple Airlines
Deal found 2/2![Multiple Airlines logo]()
$367
This Southwest deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/28:30 pm
OAK
- MDW
1 stop6h 35m
Southwest
Fri 3/69:30 pm
MDW
- OAK
Nonstop4h 40m
Southwest
Deal found 2/2![Southwest logo]()
$227
This Delta deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/2410:50 pm
SJC
- STL
1 stop8h 15m
Delta
Tue 3/316:12 pm
STL
- SJC
1 stop7h 46m
Delta
Deal found 2/4![Delta logo]()
$237
This Alaska Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/65:03 pm
OAK
- ORD
1 stop18h 08m
Alaska Airlines
Tue 3/105:29 pm
ORD
- OAK
1 stop8h 29m
Alaska Airlines
Deal found 2/2![Alaska Airlines logo]()
$257
This United Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/1612:45 am
SFO
- ORD
Nonstop4h 22m
United Airlines
Sat 5/234:30 pm
ORD
- SFO
Nonstop4h 54m
United Airlines
Deal found 2/2![United Airlines logo]()
$265
This Delta deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/55:55 am
OAK
- ORD
2 stops10h 06m
Delta
Tue 3/107:10 pm
ORD
- OAK
1 stop6h 36m
Delta
Deal found 2/2![Delta logo]()
$242
This Southwest deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/42:35 pm
SFO
- MDW
1 stop6h 15m
Southwest
Wed 3/119:05 pm
MDW
- SFO
Nonstop4h 40m
Southwest
Deal found 2/3![Southwest logo]()
$247
This Alaska Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/43:18 pm
OAK
- ORD
1 stop6h 25m
Alaska Airlines
Fri 5/157:59 pm
ORD
- OAK
1 stop20h 33m
Alaska Airlines
Deal found 2/2![Alaska Airlines logo]()
$258
This Delta deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/1012:35 pm
OAK
- ORD
1 stop6h 59m
Delta
Tue 3/173:59 pm
ORD
- OAK
2 stops9h 47m
Delta
Deal found 2/2![Delta logo]()
$242
This Southwest deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/55:45 am
OAK
- MDW
Nonstop4h 00m
Southwest
Tue 3/109:00 pm
MDW
- OAK
Nonstop4h 40m
Southwest
Deal found 2/2![Southwest logo]()
$247
This United Airlines deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/2310:45 pm
SFO
- ORD
Nonstop4h 23m
United Airlines
Sun 5/2410:45 pm
ORD
- SFO
Nonstop4h 57m
United Airlines
Deal found 2/1![United Airlines logo]()
$282
This American Airlines deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/26:00 am
SFO
- MLI
1 stop7h 03m
American Airlines
Tue 3/102:02 pm
MLI
- SFO
2 stops11h 12m
American Airlines
Deal found 2/4![American Airlines logo]()
$314
This Southwest deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/2311:55 pm
OAK
- MDW
Nonstop4h 05m
Southwest
Wed 4/298:50 pm
MDW
- OAK
Nonstop4h 35m
Southwest
Deal found 2/3![Southwest logo]()
$248
This Alaska Airlines deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/108:18 pm
SJC
- ORD
1 stop20h 45m
Alaska Airlines
Thu 5/149:00 am
ORD
- SJC
1 stop7h 19m
Alaska Airlines
Deal found 2/4![Alaska Airlines logo]()
$273
This Delta deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/255:45 am
SFO
- MDW
1 stop9h 52m
Delta
Thu 2/267:20 pm
MDW
- SFO
1 stop6h 27m
Delta
Deal found 2/1![Delta logo]()
$252
This Southwest deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/145:15 am
SFO
- MDW
Nonstop3h 55m
Southwest
Wed 3/189:05 pm
MDW
- SFO
Nonstop4h 40m
Southwest
Deal found 2/4![Southwest logo]()
$250
This Alaska Airlines deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/89:43 am
OAK
- ORD
2 stops12h 16m
Alaska Airlines
Thu 4/236:00 am
ORD
- OAK
1 stop9h 15m
Alaska Airlines
Deal found 2/4![Alaska Airlines logo]()
$275
This Delta deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/1710:55 pm
SFO
- MDW
1 stop7h 52m
Delta
Tue 4/211:23 pm
MDW
- SFO
1 stop7h 40m
Delta
Deal found 2/2![Delta logo]()
$252
This United Airlines deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/311:56 pm
SFO
- ORD
Nonstop4h 24m
United Airlines
Wed 5/136:20 am
ORD
- SFO
Nonstop4h 51m
United Airlines
Deal found 2/4![United Airlines logo]()
$307
This Southwest deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/65:10 am
SFO
- MDW
Nonstop4h 00m
Southwest
Mon 3/99:25 pm
MDW
- SFO
Nonstop4h 40m
Southwest
Deal found 2/4![Southwest logo]()
$250
This Delta deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/42:39 pm
SFO
- ORD
1 stop7h 13m
Delta
Fri 3/65:37 pm
ORD
- SFO
1 stop7h 48m
Delta
Deal found 2/1![Delta logo]()
$252
This United Airlines deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/811:56 pm
SFO
- ORD
Nonstop4h 24m
United Airlines
Sun 5/1010:45 pm
ORD
- SFO
Nonstop4h 50m
United Airlines
Deal found 2/4![United Airlines logo]()
$307
This Alaska Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/246:15 am
OAK
- ORD
1 stop15h 41m
Alaska Airlines
Wed 2/253:54 pm
ORD
- OAK
1 stop8h 55m
Alaska Airlines
Deal found 2/2![Alaska Airlines logo]()
$280
This American Airlines deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/223:02 pm
SFO
- MLI
1 stop6h 52m
American Airlines
Sat 4/2512:52 pm
MLI
- SFO
1 stop10h 36m
American Airlines
Deal found 2/4![American Airlines logo]()
$399
Last-minute flights from San Francisco Bay Area to IllinoisDiscover last-minute flight deals from San Francisco Bay Area to Illinois. Data last updated February 5, 2026 and is based on user searches.
Discover last-minute flight deals from San Francisco Bay Area to Illinois. Data last updated February 5, 2026 and is based on user searches.
This Frontier deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/257:20 am
SFO
- STL
1 stop6h 33m
Frontier
Sat 2/282:51 pm
STL
- SFO
1 stop11h 37m
Frontier
Deal found 2/3![Frontier logo]()
$158
This Expedia deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/266:15 am
SFO
- STL
1 stop28h 54m
Frontier
Mon 3/210:11 pm
STL
- SFO
1 stop22h 09m
Frontier
Deal found 2/2![Frontier logo]()
$168
This Priceline deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/286:15 am
SFO
- STL
1 stop5h 41m
Frontier
Wed 3/118:12 pm
STL
- SFO
1 stop6h 16m
Frontier
Deal found 2/4![Frontier logo]()
$179
This Kiwi.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/69:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/98:12 pm
STL
- SFO
1 stop25h 57m
Frontier
Deal found 2/1![Frontier logo]()
$151
This Kiwi.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/69:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Wed 3/1112:14 pm
STL
- SFO
1 stop21h 44m
Frontier
Deal found 2/1![Frontier logo]()
$177
This Kiwi.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/89:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/98:12 pm
STL
- SFO
1 stop25h 57m
Frontier
Deal found 2/1![Frontier logo]()
$170
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/109:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/168:12 pm
STL
- SFO
1 stop30h 16m
Frontier
Deal found 2/3![Frontier logo]()
$156
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/109:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/238:12 pm
STL
- SFO
1 stop30h 16m
Frontier
Deal found 2/3![Frontier logo]()
$183
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/109:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Sun 3/158:06 pm
STL
- SFO
2 stops51h 32m
Frontier
Deal found 2/3![Frontier logo]()
$191
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/117:32 pm
SFO
- STL
1 stop21h 39m
Frontier
Mon 3/168:12 pm
STL
- SFO
1 stop30h 16m
Frontier
Deal found 2/3![Frontier logo]()
$185
This Southwest deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/1111:55 pm
OAK
- MDW
Nonstop4h 00m
Southwest
Mon 3/169:30 pm
MDW
- OAK
Nonstop4h 40m
Southwest
Deal found 2/4![Southwest logo]()
$217
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/129:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Mon 3/168:12 pm
STL
- SFO
1 stop30h 16m
Frontier
Deal found 2/3![Frontier logo]()
$193
One-way flights from San Francisco Bay Area to IllinoisSearch for one-way flight options from San Francisco Bay Area to Illinois. Find affordable one-way fares based on user searches. Data last updated February 5, 2026.
Search for one-way flight options from San Francisco Bay Area to Illinois. Find affordable one-way fares based on user searches. Data last updated February 5, 2026.
This Trip.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/109:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Deal found 2/3![Frontier logo]()
$60
This Trip.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/98:20 pm
SJC
- ORD
1 stop7h 48m
Frontier
Deal found 2/3![Frontier logo]()
$67
This Trip.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/69:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Deal found 2/2![Frontier logo]()
$71
This WAYA deal was found by Cheapflights users on 2/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WAYA is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/257:20 am
SFO
- STL
1 stop6h 33m
Frontier
Deal found 2/5![Frontier logo]()
$74
This Trip.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/118:20 pm
SJC
- ORD
1 stop8h 27m
Frontier
Deal found 2/2![Frontier logo]()
$74
This Trip.com deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/237:42 pm
SJC
- ORD
1 stop8h 26m
Frontier
Deal found 2/4![Frontier logo]()
$75
This Trip.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/278:20 pm
SJC
- ORD
1 stop8h 27m
Frontier
Deal found 2/3![Frontier logo]()
$76
This Kiwi.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/48:20 pm
SJC
- ORD
1 stop8h 27m
Frontier
Deal found 2/2![Frontier logo]()
$81
This Frontier deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/47:35 am
SFO
- STL
1 stop6h 18m
Frontier
Deal found 2/3![Frontier logo]()
$84
This Super.com deal was found by Cheapflights users on 2/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/266:15 am
SFO
- STL
1 stop28h 54m
Frontier
Deal found 2/4![Frontier logo]()
$88
This Trip.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/167:42 pm
SJC
- ORD
1 stop8h 26m
Frontier
Deal found 2/3![Frontier logo]()
$88
This Trip.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/198:20 pm
SJC
- ORD
1 stop8h 27m
Frontier
Deal found 2/2![Frontier logo]()
$89
Find flight deals from San Francisco Bay Area to Illinois
Keep the following information in mind while searching for San Francisco Bay Area to Illinois flight deals. Data was last updated February 5, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $151 (Kiwi.com) |
One-way from | $60 (Trip.com) |
Popular in | November |
Cheapest in | September |
Average price | $297 |
Cheapflights Fare Finder
Customize your flight search to find flights from San Francisco Bay Area to Illinois that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 5, 2026.
Use the filters below to find and compare flights from San Francisco Bay Area to Illinois that are best for you.
Fly from
San Francisco Bay Area
Fly to
Illinois
Route
Depart
Return
Price
OaklandChicago
OAK - MDW
OAKMDW
Oakland
Sat 3/14
5:40 am-11:40 am
Nonstop4h 00m
Chicago Midway
Tue 3/17
9:00 pm-11:40 pm
Nonstop4h 40m
$217
San JoseChicago
SJC - ORD
SJCORD
San Jose
Tue 3/3
2:50 pm-11:59 pm
1 stop7h 09m
Chicago O'Hare Intl
Tue 3/10
8:20 am-2:13 pm
1 stop7h 53m
$223
OaklandChicago
OAK - MDW
OAKMDW
Oakland
Mon 3/2
8:30 pm-5:05 am
1 stop6h 35m
Chicago Midway
Fri 3/6
9:30 pm-12:10 am
Nonstop4h 40m
$227
San FranciscoSt. Louis
SFO - STL
SFOSTL
San Francisco
Fri 4/24
10:35 pm-8:30 am
1 stop7h 55m
Lambert-St Louis
Mon 4/27
1:45 pm-10:25 pm
1 stop10h 40m
$237
San JoseSt. Louis
SJC - STL
SJCSTL
San Jose
Tue 3/24
10:50 pm-9:05 am
1 stop8h 15m
Lambert-St Louis
Tue 3/31
6:12 pm-11:58 pm
1 stop7h 46m
$237
OaklandChicago
OAK - ORD
OAKORD
Oakland
Thu 3/5
5:55 am-6:01 pm
2 stops10h 06m
Chicago O'Hare Intl
Tue 3/10
7:10 pm-11:46 pm
1 stop6h 36m
$242
OaklandChicago
OAK - ORD
OAKORD
Oakland
Tue 3/10
12:35 pm-9:34 pm
1 stop6h 59m
Chicago O'Hare Intl
Tue 3/17
3:59 pm-11:46 pm
2 stops9h 47m
$242
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Wed 3/4
2:35 pm-10:50 pm
1 stop6h 15m
Chicago Midway
Wed 3/11
9:05 pm-11:45 pm
Nonstop4h 40m
$247
OaklandChicago
OAK - MDW
OAKMDW
Oakland
Thu 3/5
5:45 am-11:45 am
Nonstop4h 00m
Chicago Midway
Tue 3/10
9:00 pm-11:40 pm
Nonstop4h 40m
$247
OaklandChicago
OAK - MDW
OAKMDW
Oakland
Thu 4/23
11:55 pm-6:00 am
Nonstop4h 05m
Chicago Midway
Wed 4/29
8:50 pm-11:25 pm
Nonstop4h 35m
$248
Showing 1-10 of 60 results
Best time to book a flight from San Francisco Bay Area to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from San Francisco Bay Area with our price prediction graph.
SFO-STL
OAK-ORD
OAK-MDW
SJC-ORD
SFO-ORD
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from San Francisco Bay Area to Illinois
zzXIH-USIL
SFO-STL
OAK-ORD
OAK-MDW
SJC-ORD
What is the cheapest month to book a flight from San Francisco Bay Area to Illinois?
Currently, October is the cheapest month in which you can book a flight from San Francisco Bay Area to Illinois (average of $125). Flying from San Francisco Bay Area to Illinois in December is currently the most expensive (average of $233). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from XIH to IL?
Find hourly flight availability from San Francisco Bay Area to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated February 5, 2026.
Unlike at noon, when flights are generally more expensive, you can save up to 32% on flights from San Francisco Bay Area to Illinois by exploring options for tickets in the afternoon.
What is the cheapest day to fly from San Francisco Bay Area to Illinois?
Use this chart to determine the cheapest time to fly round-trip from San Francisco Bay Area to Illinois. Price data was last updated on January 31, 2026.
Travelers seeking maximum savings on their San Francisco Bay Area to Illinois flight should consider departing on Saturday afternoons when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
Weekly flight availability from San Francisco Bay Area to Illinois
Explore weekly flight availability from San Francisco Bay Area to Illinois. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated February 5, 2026.
The most flights from zzXIH to USIL are scheduled on a Monday (54 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (29 on average).
Reviews of airlines servicing Illinois
Get insights into the airlines that provide service to Illinois. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Illinois. Reviews last updated February 5, 2026.
See what other customers who have flown with Alaska Airlines, Southwest, and United Airlines from San Francisco Bay Area to Illinois have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Comfort
7.8
Boarding
8.1
Entertainment
7.0
Food
7.1
Crew
8.5
Overall
8.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Comfort
7.8
Boarding
8.1
Entertainment
7.0
Food
7.1
Crew
8.5
Overall
8.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Comfort
7.8
Boarding
8.1
Entertainment
7.0
Food
7.1
Crew
8.5
Overall
8.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Comfort
7.8
Boarding
8.1
Entertainment
7.0
Food
7.1
Crew
8.5
Overall
8.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Comfort
7.8
Boarding
8.1
Entertainment
7.0
Food
7.1
Crew
8.5
Overall
8.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Comfort
7.8
Boarding
8.1
Entertainment
7.0
Food
7.1
Crew
8.5
Overall
8.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Related info for your journey
Find useful and relevant information for your journey from San Francisco Bay Area to Illinois. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Alternative routes for San Francisco Bay Area to Illinois
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Illinois by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from San Francisco Bay Area to Illinois by cabin class
Find flights from San Francisco Bay Area to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
San Francisco Bay Area and Illinois flights
Browse other San Francisco Bay Area and Illinois flight options. Last updated on February 5, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Find a return flight route from Illinois
Find the right flight back to San Francisco Bay Area after your stay in Illinois
San Francisco Bay Area to Illinois flights
Consider these flights traveling from San Francisco Bay Area to Illinois.
Top 9 airlines flying from San Francisco Bay Area to Illinois
Discover the top 9 airlines that operate flights from San Francisco Bay Area to Illinois. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 5, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$62 | Average$241 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$101 | Average$277 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$108 | Average$230 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$128 | Average$351 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$133 | Average$445 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$170 | Average$397 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$185 | Average$427 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$197 | Average$545 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$234 | Average$275 | FlexibilityNo cancel fee | On-time62% |