$60+ Cheap flights from San Francisco (SFO) 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 6 — Mar 131
1 adult, Economy
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Find cheap flights from San Francisco 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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Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from San Francisco to Illinois
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Cheapest flights from San Francisco to IllinoisExplore the most affordable flight options available from San Francisco to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 4, 2026.
Explore the most affordable flight options available from San Francisco to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 4, 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 2/2. 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 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 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 2/3. 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.
Thu 5/1411:16 pm
SFO
- STL
1 stop12h 56m
Frontier
Mon 5/183:02 pm
STL
- SFO
1 stop9h 29m
Frontier
Deal found 2/3![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 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
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.
Tue 2/1710:55 pm
SFO
- ORD
1 stop9h 44m
Frontier
Fri 2/2012:53 pm
ORD
- SFO
1 stop13h 35m
Frontier
Deal found 2/3![Frontier logo]()
$246
Best flights from San Francisco to IllinoisDiscover carefully curated flight deals from San Francisco to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 4, 2026.
Discover carefully curated flight deals from San Francisco to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 4, 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.
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 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 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.
Wed 4/810:50 pm
SFO
- ORD
Nonstop4h 37m
United Airlines
Sun 4/126:25 am
ORD
- SFO
Nonstop4h 51m
United Airlines
Deal found 2/2![United Airlines logo]()
$252
This CheapOair 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/179:33 pm
SFO
- STL
1 stop15h 48m
Frontier
Sun 4/199:55 pm
STL
- SFO
1 stop12h 23m
Frontier
Deal found 2/3![Frontier logo]()
$291
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 4/247:00 am
SFO
- ORD
1 stop21h 40m
Alaska Airlines
Mon 4/273:52 pm
ORD
- SFO
1 stop9h 09m
Alaska Airlines
Deal found 2/2![Alaska Airlines logo]()
$293
This American 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/411:30 pm
SFO
- PIA
1 stop7h 50m
American Airlines
Wed 3/116:50 pm
PIA
- SFO
1 stop6h 54m
American Airlines
Deal found 2/3![American Airlines logo]()
$309
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 2/3. 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.
Fri 3/65:10 am
SFO
- MDW
Nonstop4h 00m
Southwest
Tue 3/1010:05 am
MDW
- SFO
Nonstop4h 40m
Southwest
Deal found 2/3![Southwest logo]()
$250
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.
Mon 3/210:50 pm
SFO
- ORD
Nonstop4h 22m
United Airlines
Thu 5/288:06 pm
ORD
- SFO
Nonstop4h 53m
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.
Fri 4/249:35 pm
SFO
- MDW
1 stop10h 21m
Delta
Mon 4/279:27 am
MDW
- SFO
1 stop7h 28m
Delta
Deal found 2/2![Delta logo]()
$267
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 3/115:40 am
SFO
- MDW
Nonstop4h 00m
Southwest
Thu 3/126:05 am
MDW
- SFO
1 stop7h 35m
Southwest
Deal found 2/3![Southwest logo]()
$260
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.
Fri 5/17:00 pm
SFO
- ORD
Nonstop4h 28m
United Airlines
Mon 5/49:31 pm
ORD
- SFO
Nonstop4h 59m
United Airlines
Deal found 2/1![United Airlines logo]()
$283
This American 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/76:00 am
SFO
- PIA
1 stop6h 17m
American Airlines
Wed 3/115:15 am
PIA
- SFO
2 stops11h 19m
American Airlines
Deal found 2/1![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.
Fri 4/175:15 am
SFO
- MDW
Nonstop4h 10m
Southwest
Tue 4/219:00 pm
MDW
- SFO
Nonstop4h 35m
Southwest
Deal found 2/3![Southwest logo]()
$270
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.
Mon 2/1610:58 pm
SFO
- STL
1 stop29h 53m
Frontier
Wed 2/188:17 pm
STL
- SFO
1 stop27h 22m
Frontier
Deal found 2/3![Frontier logo]()
$331
This Delta 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/2510:20 am
SFO
- STL
2 stops11h 03m
Delta
Sat 2/287:00 am
STL
- SFO
2 stops13h 53m
Delta
Deal found 2/3![Delta logo]()
$303
This Alaska 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/86:30 am
SFO
- STL
1 stop15h 29m
Alaska Airlines
Tue 3/107:00 am
STL
- SFO
1 stop9h 02m
Alaska Airlines
Deal found 2/1![Alaska Airlines logo]()
$343
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.
Wed 3/255:40 am
SFO
- MDW
Nonstop4h 00m
Southwest
Mon 3/306:25 pm
MDW
- SFO
1 stop7h 45m
Southwest
Deal found 2/2![Southwest logo]()
$272
This United 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/2711:59 pm
SFO
- ORD
Nonstop4h 20m
United Airlines
Thu 4/22:15 pm
ORD
- SFO
Nonstop4h 57m
United Airlines
Deal found 2/3![United Airlines logo]()
$303
This American 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/1711:30 pm
SFO
- PIA
1 stop7h 41m
American Airlines
Sat 2/215:00 am
PIA
- SFO
1 stop6h 40m
American Airlines
Deal found 2/2![American Airlines logo]()
$359
This KAYAK 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/1010:54 pm
SFO
- STL
1 stop8h 40m
Delta
Thu 2/125:29 pm
STL
- SFO
1 stop8h 18m
Delta
Deal found 2/3![Delta logo]()
$329
This United 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/911:30 pm
SFO
- DEC
1 stop7h 16m
United Airlines
Tue 6/166:55 pm
DEC
- SFO
1 stop7h 35m
United Airlines
Deal found 2/3![United Airlines logo]()
$304
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.
Fri 3/69:39 pm
SFO
- RFD
1 stop11h 34m
Multiple Airlines
Mon 3/99:41 pm
RFD
- SFO
2 stops22h 56m
Multiple Airlines
Deal found 2/2![Multiple Airlines logo]()
$405
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/210:55 pm
SFO
- MDW
1 stop8h 25m
Southwest
Tue 4/79:00 pm
MDW
- SFO
Nonstop4h 35m
Southwest
Deal found 2/1![Southwest logo]()
$280
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.
Fri 2/276:30 am
SFO
- STL
1 stop29h 21m
Alaska Airlines
Sun 3/17:00 am
STL
- SFO
1 stop18h 59m
Alaska Airlines
Deal found 2/3![Alaska Airlines logo]()
$383
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.
Mon 2/2310:50 pm
SFO
- ORD
Nonstop4h 22m
United Airlines
Sun 3/16:25 am
ORD
- SFO
Nonstop5h 05m
United Airlines
Deal found 2/2![United Airlines logo]()
$305
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/252:25 pm
SFO
- MDW
1 stop7h 40m
Southwest
Tue 4/74:00 pm
MDW
- SFO
2 stops9h 15m
Southwest
Deal found 2/1![Southwest logo]()
$282
This American 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/611:30 pm
SFO
- CMI
1 stop7h 51m
American Airlines
Mon 3/92:54 pm
CMI
- SFO
1 stop10h 22m
American Airlines
Deal found 2/2![American Airlines logo]()
$398
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.
Sun 4/56:29 pm
SFO
- ORD
Nonstop4h 30m
United Airlines
Sat 4/187:40 am
ORD
- SFO
Nonstop4h 58m
United Airlines
Deal found 2/1![United Airlines logo]()
$306
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/15:15 am
SFO
- MDW
Nonstop4h 10m
Southwest
Mon 5/49:45 pm
MDW
- SFO
Nonstop4h 35m
Southwest
Deal found 2/1![Southwest logo]()
$283
Last-minute flights from San Francisco to IllinoisDiscover last-minute flight deals from San Francisco to Illinois. Data last updated February 4, 2026 and is based on user searches.
Discover last-minute flight deals from San Francisco to Illinois. Data last updated February 4, 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 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 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 Expedia 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/108:25 am
SFO
- ORD
2 stops13h 34m
Multiple Airlines
Tue 3/178:55 pm
ORD
- SFO
1 stop23h 42m
Multiple Airlines
Deal found 2/3![Multiple Airlines logo]()
$248
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 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 to IllinoisSearch for one-way flight options from San Francisco to Illinois. Find affordable one-way fares based on user searches. Data last updated February 4, 2026.
Search for one-way flight options from San Francisco to Illinois. Find affordable one-way fares based on user searches. Data last updated February 4, 2026.
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.
Tue 3/109:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Deal found 2/4![Frontier logo]()
$60
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.
Fri 3/69:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Deal found 2/4![Frontier logo]()
$71
This Mytrip 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 Mytrip 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 2/4![Frontier logo]()
$74
This Booking.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 Booking.com 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 2/4![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 2/2. 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.
Tue 3/249:04 pm
SFO
- STL
1 stop10h 45m
Frontier
Deal found 2/2![Frontier logo]()
$90
This Kiwi.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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/99:24 pm
SFO
- STL
2 stops34h 25m
Frontier
Deal found 2/4![Frontier logo]()
$91
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 3/168:09 pm
SFO
- STL
1 stop14h 06m
Frontier
Deal found 2/4![Frontier logo]()
$92
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.
Tue 2/1710:55 pm
SFO
- MDW
1 stop18h 12m
Frontier
Deal found 2/2![Frontier logo]()
$110
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.
Mon 3/1610:35 pm
SFO
- ORD
2 stops29h 33m
Frontier
Deal found 2/3![Frontier logo]()
$110
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.
Sat 4/2510:10 am
SFO
- MDW
1 stop5h 30m
Southwest
Deal found 2/2![Southwest logo]()
$112
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 3/47:15 pm
SFO
- ORD
2 stops13h 31m
Frontier
Deal found 2/3![Frontier logo]()
$112
Find flight deals from San Francisco to Illinois
Keep the following information in mind while searching for San Francisco to Illinois flight deals. Data was last updated February 4, 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 |
Good round-trip deal | $324 or less |
Good one-way deal | $154 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from San Francisco 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 4, 2026.
Use the filters below to find and compare flights from San Francisco to Illinois that are best for you.
Fly from
San Francisco
Fly to
Illinois
Route
Depart
Return
Price
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
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Fri 3/6
5:10 am-11:10 am
Nonstop4h 00m
Chicago Midway
Tue 3/10
10:05 am-12:45 pm
Nonstop4h 40m
$250
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Wed 2/25
5:45 am-5:37 pm
1 stop9h 52m
Chicago Midway
Thu 2/26
7:20 pm-11:47 pm
1 stop6h 27m
$252
San FranciscoChicago
SFO - ORD
SFOORD
San Francisco
Wed 4/8
10:50 pm-5:27 am
Nonstop4h 37m
Chicago O'Hare Intl
Sun 4/12
6:25 am-9:16 am
Nonstop4h 51m
$252
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Wed 3/11
5:40 am-11:40 am
Nonstop4h 00m
Chicago Midway
Thu 3/12
6:05 am-11:40 am
1 stop7h 35m
$260
San FranciscoChicago
SFO - ORD
SFOORD
San Francisco
Mon 3/2
10:50 pm-5:12 am
Nonstop4h 22m
Chicago O'Hare Intl
Thu 5/28
8:06 pm-10:59 pm
Nonstop4h 53m
$265
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Fri 4/24
9:35 pm-9:56 am
1 stop10h 21m
Chicago Midway
Mon 4/27
9:27 am-2:55 pm
1 stop7h 28m
$267
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Fri 4/17
5:15 am-11:25 am
Nonstop4h 10m
Chicago Midway
Tue 4/21
9:00 pm-11:35 pm
Nonstop4h 35m
$270
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Wed 3/25
5:40 am-11:40 am
Nonstop4h 00m
Chicago Midway
Mon 3/30
6:25 pm-12:10 am
1 stop7h 45m
$272
San FranciscoChicago
SFO - MDW
SFOMDW
San Francisco
Thu 4/2
10:55 pm-9:20 am
1 stop8h 25m
Chicago Midway
Tue 4/7
9:00 pm-11:35 pm
Nonstop4h 35m
$280
Showing 1-10 of 60 results
Best time to book a flight from San Francisco to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from San Francisco with our price prediction graph.
SFO-STL
SFO-MDW
SFO-ORD
SFO-RFD
SFO-PIA
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 to Illinois
SFO-USIL
SFO-STL
SFO-MDW
SFO-ORD
SFO-RFD
What is the cheapest month to book a flight from San Francisco to Illinois?
Currently, October is the cheapest month in which you can book a flight from San Francisco to Illinois (average of $125). Flying from San Francisco 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 SFO to IL?
Find hourly flight availability from San Francisco 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 4, 2026.
It’s optimal to fly from San Francisco to Illinois in the afternoon. By choosing this option you can save up to 28% on the cost of your flight, compared to a flight at noon.
What is the cheapest day to fly from San Francisco to Illinois?
Use this chart to determine the cheapest time to fly round-trip from San Francisco to Illinois. Price data was last updated on January 31, 2026.
Travelers seeking maximum savings on their San Francisco 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 to Illinois
Explore weekly flight availability from San Francisco 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 4, 2026.
The most flights from SFO 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 4, 2026.
Get a feel of what it's like to fly with Alaska Airlines, Southwest, and United Airlines from San Francisco to Illinois by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Food
7.1
Comfort
7.8
Crew
8.5
Boarding
8.1
Overall
8.0
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Food
7.1
Comfort
7.8
Crew
8.5
Boarding
8.1
Overall
8.0
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Food
7.1
Comfort
7.8
Crew
8.5
Boarding
8.1
Overall
8.0
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Food
7.1
Comfort
7.8
Crew
8.5
Boarding
8.1
Overall
8.0
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Food
7.1
Comfort
7.8
Crew
8.5
Boarding
8.1
Overall
8.0
Entertainment
7.0
Reviews
1 / 20
10.0
ExcellentAnonymous,Jan 2026
STS - LAX
Food
7.1
Comfort
7.8
Crew
8.5
Boarding
8.1
Overall
8.0
Entertainment
7.0
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 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 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 to Illinois by cabin class
Find flights from San Francisco to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
San Francisco and Illinois flights
Browse other San Francisco and Illinois flight options. Last updated on February 4, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
San Francisco to Illinois flights
Consider these flights traveling from San Francisco to Illinois.
Top 8 airlines flying from San Francisco to Illinois
Discover the top 8 airlines that operate flights from San Francisco 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 4, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$101 | Average$277 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$126 | Average$240 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$128 | Average$323 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$133 | Average$457 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$185 | Average$351 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$196 | Average$332 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$197 | Average$500 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$234 | Average$275 | FlexibilityNo cancel fee | On-time62% |