$99+ Cheap flights from San Diego (SAN) 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 6/8. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — ORD
Jun 26 — Jul 31
Round-trip
1 adult, Economy
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Cheapest flights from San Diego to IllinoisExplore the most affordable flight options available from San Diego to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 27, 2026.
Explore the most affordable flight options available from San Diego to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 27, 2026.
This Expedia deal was found by Cheapflights users on 5/26. 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 6/116:25 am
SAN
- STL
1 stop9h 53m
Frontier
Tue 6/167:46 pm
STL
- SAN
1 stop15h 02m
Frontier
Deal found 5/26![Frontier logo]()
$198
This Super.com deal was found by Cheapflights users on 5/24. 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.
Tue 6/97:30 am
SAN
- STL
1 stop9h 04m
Frontier
Thu 6/117:38 pm
STL
- SAN
1 stop15h 31m
Frontier
Deal found 5/24![Frontier logo]()
$204
This Trip.com deal was found by Cheapflights users on 5/26. 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.
Wed 7/19:46 am
SAN
- STL
1 stop7h 05m
Frontier
Mon 7/67:10 pm
STL
- SAN
1 stop20h 58m
Frontier
Deal found 5/26![Frontier logo]()
$210
This Trip.com deal was found by Cheapflights users on 5/23. 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 6/169:43 am
SAN
- STL
1 stop7h 08m
Frontier
Wed 6/177:46 pm
STL
- SAN
1 stop15h 02m
Frontier
Deal found 5/23![Frontier logo]()
$211
This Trip.com deal was found by Cheapflights users on 5/24. 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 6/76:25 am
SAN
- STL
1 stop10h 58m
Frontier
Wed 6/107:03 pm
STL
- SAN
1 stop15h 45m
Frontier
Deal found 5/24![Frontier logo]()
$216
This Frontier deal was found by Cheapflights users on 5/26. 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 6/186:25 am
SAN
- STL
1 stop9h 53m
Frontier
Mon 6/227:38 pm
STL
- SAN
1 stop6h 15m
Frontier
Deal found 5/26![Frontier logo]()
$228
This Priceline deal was found by Cheapflights users on 5/24. 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.
Thu 7/236:35 am
SAN
- STL
1 stop6h 21m
Frontier
Tue 7/288:08 pm
STL
- SAN
1 stop5h 43m
Frontier
Deal found 5/24![Frontier logo]()
$234
This Booking.com deal was found by Cheapflights users on 5/24. 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.
Mon 8/38:51 pm
SAN
- STL
1 stop19h 14m
Frontier
Fri 8/78:08 pm
STL
- SAN
1 stop5h 43m
Frontier
Deal found 5/24![Frontier logo]()
$240
This Trip.com deal was found by Cheapflights users on 5/25. 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.
Thu 7/236:35 am
SAN
- STL
1 stop6h 21m
Frontier
Sun 7/267:10 pm
STL
- SAN
1 stop26h 56m
Frontier
Deal found 5/25![Frontier logo]()
$241
This Expedia deal was found by Cheapflights users on 5/22. 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.
Mon 6/226:25 am
SAN
- STL
1 stop9h 53m
Frontier
Sun 6/282:56 pm
STL
- SAN
1 stop19h 52m
Frontier
Deal found 5/22![Frontier logo]()
$244
This Frontier deal was found by Cheapflights users on 5/24. 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.
Mon 6/86:25 am
SAN
- STL
1 stop10h 58m
Frontier
Fri 6/127:38 pm
STL
- SAN
1 stop6h 15m
Frontier
Deal found 5/24![Frontier logo]()
$249
This Frontier deal was found by Cheapflights users on 5/22. 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 6/246:25 am
SAN
- STL
1 stop10h 58m
Frontier
Tue 6/308:08 pm
STL
- SAN
1 stop5h 45m
Frontier
Deal found 5/22![Frontier logo]()
$250
Best flights from San Diego to IllinoisDiscover carefully curated flight deals from San Diego to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated May 27, 2026.
Discover carefully curated flight deals from San Diego to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated May 27, 2026.
This Kiwi.com deal was found by Cheapflights users on 5/25. 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 7/144:12 pm
SAN
- RFD
1 stop25h 47m
Multiple Airlines
Fri 7/179:13 pm
RFD
- SAN
1 stop20h 14m
Multiple Airlines
Deal found 5/25![Multiple Airlines logo]()
$278
This Delta deal was found by Cheapflights users on 5/22. 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 6/192:31 pm
SAN
- STL
1 stop7h 25m
Delta
Fri 6/265:36 pm
STL
- SAN
1 stop7h 59m
Delta
Deal found 5/22![Delta logo]()
$297
This Alaska Airlines deal was found by Cheapflights users on 5/23. 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 6/105:23 pm
SAN
- ORD
Nonstop4h 13m
Alaska Airlines
Sat 6/136:20 am
ORD
- SAN
Nonstop4h 34m
Alaska Airlines
Deal found 5/23![Alaska Airlines logo]()
$317
This United Airlines deal was found by Cheapflights users on 5/26. 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 6/910:55 am
SAN
- ORD
1 stop7h 16m
United Airlines
Thu 6/118:10 pm
ORD
- SAN
Nonstop4h 29m
United Airlines
Deal found 5/26![United Airlines logo]()
$327
This Southwest deal was found by Cheapflights users on 5/22. 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 8/1410:40 pm
SAN
- MDW
Nonstop3h 50m
Southwest
Wed 8/198:25 pm
MDW
- SAN
Nonstop4h 10m
Southwest
Deal found 5/22![Southwest logo]()
$332
This American Airlines deal was found by Cheapflights users on 5/26. 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 7/156:20 am
SAN
- BMI
1 stop7h 36m
American Airlines
Sat 7/185:00 am
BMI
- SAN
1 stop6h 08m
American Airlines
Deal found 5/26![American Airlines logo]()
$349
This Kiwi.com deal was found by Cheapflights users on 5/22. 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 7/224:38 pm
SAN
- RFD
2 stops17h 46m
Multiple Airlines
Mon 7/279:13 pm
RFD
- SAN
1 stop20h 14m
Multiple Airlines
Deal found 5/22![Multiple Airlines logo]()
$288
This Delta deal was found by Cheapflights users on 5/24. 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 10/710:30 pm
SAN
- MDW
1 stop8h 15m
Delta
Sat 10/105:25 pm
MDW
- SAN
1 stop7h 38m
Delta
Deal found 5/24![Delta logo]()
$327
This Alaska Airlines deal was found by Cheapflights users on 5/26. 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.
Sat 8/227:03 am
SAN
- ORD
Nonstop4h 19m
Alaska Airlines
Mon 8/247:59 pm
ORD
- SAN
Nonstop4h 37m
Alaska Airlines
Deal found 5/26![Alaska Airlines logo]()
$332
This Kiwi.com deal was found by Cheapflights users on 5/25. 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 7/83:03 pm
SAN
- RFD
1 stop19h 21m
Multiple Airlines
Sat 7/1812:58 pm
RFD
- SAN
1 stop28h 29m
Multiple Airlines
Deal found 5/25![Multiple Airlines logo]()
$305
This Southwest deal was found by Cheapflights users on 5/23. 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 8/146:45 am
SAN
- STL
1 stop7h 35m
Southwest
Fri 8/146:40 pm
STL
- SAN
1 stop5h 15m
Southwest
Deal found 5/23![Southwest logo]()
$338
This American Airlines deal was found by Cheapflights users on 5/22. 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 6/1210:45 pm
SAN
- PIA
1 stop8h 43m
American Airlines
Mon 6/157:11 pm
PIA
- SAN
1 stop6h 37m
American Airlines
Deal found 5/22![American Airlines logo]()
$349
This United Airlines deal was found by Cheapflights users on 5/27. 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 8/212:15 pm
SAN
- MLI
1 stop6h 59m
United Airlines
Mon 8/241:15 pm
MLI
- SAN
2 stops8h 40m
United Airlines
Deal found 5/27![United Airlines logo]()
$354
This Alaska Airlines deal was found by Cheapflights users on 5/24. 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.
Thu 6/185:23 pm
SAN
- ORD
Nonstop4h 13m
Alaska Airlines
Tue 6/237:59 pm
ORD
- SAN
Nonstop4h 34m
Alaska Airlines
Deal found 5/24![Alaska Airlines logo]()
$336
This Southwest deal was found by Cheapflights users on 5/24. 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.
Tue 8/46:20 am
SAN
- STL
1 stop6h 10m
Southwest
Tue 8/118:25 am
STL
- SAN
Nonstop3h 45m
Southwest
Deal found 5/24![Southwest logo]()
$343
This Kiwi.com deal was found by Cheapflights users on 5/26. 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 9/177:24 pm
SAN
- RFD
1 stop20h 47m
Multiple Airlines
Mon 9/218:44 pm
RFD
- SAN
1 stop14h 18m
Multiple Airlines
Deal found 5/26![Multiple Airlines logo]()
$314
This Delta deal was found by Cheapflights users on 5/26. 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 10/2212:50 pm
SAN
- MLI
1 stop7h 40m
Delta
Mon 10/2611:00 am
MLI
- SAN
1 stop9h 42m
Delta
Deal found 5/26![Delta logo]()
$349
This United Airlines deal was found by Cheapflights users on 5/22. 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 7/2910:25 pm
SAN
- ORD
Nonstop4h 11m
United Airlines
Sun 8/27:01 am
ORD
- SAN
Nonstop4h 28m
United Airlines
Deal found 5/22![United Airlines logo]()
$356
This KAYAK deal was found by Cheapflights users on 5/26. 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.
Mon 8/310:45 pm
SAN
- ORD
Nonstop4h 15m
American Airlines
Wed 8/56:45 am
ORD
- SAN
Nonstop4h 13m
American Airlines
Deal found 5/26![American Airlines logo]()
$359
This Kiwi.com deal was found by Cheapflights users on 5/26. 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 8/204:17 pm
SAN
- RFD
1 stop18h 06m
Multiple Airlines
Sun 8/239:35 pm
RFD
- SAN
1 stop25h 23m
Multiple Airlines
Deal found 5/26![Multiple Airlines logo]()
$314
This Alaska Airlines deal was found by Cheapflights users on 5/25. 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.
Thu 7/95:23 pm
SAN
- ORD
Nonstop4h 13m
Alaska Airlines
Wed 7/156:20 am
ORD
- SAN
Nonstop4h 34m
Alaska Airlines
Deal found 5/25![Alaska Airlines logo]()
$356
This Southwest deal was found by Cheapflights users on 5/22. 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 6/226:30 am
SAN
- MDW
Nonstop4h 05m
Southwest
Mon 6/295:45 am
MDW
- SAN
Nonstop4h 05m
Southwest
Deal found 5/22![Southwest logo]()
$357
This Delta deal was found by Cheapflights users on 5/26. 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 7/2410:30 pm
SAN
- MLI
1 stop9h 42m
Delta
Mon 8/35:09 pm
MLI
- SAN
1 stop7h 51m
Delta
Deal found 5/26![Delta logo]()
$374
This American Airlines deal was found by Cheapflights users on 5/24. 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 6/106:15 am
SAN
- BMI
1 stop9h 14m
American Airlines
Wed 6/246:02 pm
BMI
- SAN
1 stop7h 46m
American Airlines
Deal found 5/24![American Airlines logo]()
$383
This Alaska Airlines deal was found by Cheapflights users on 5/23. 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 7/512:40 pm
SAN
- ORD
Nonstop4h 17m
Alaska Airlines
Thu 7/162:20 pm
ORD
- SAN
Nonstop4h 39m
Alaska Airlines
Deal found 5/23![Alaska Airlines logo]()
$357
This Southwest deal was found by Cheapflights users on 5/23. 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 7/1510:40 pm
SAN
- MDW
Nonstop4h 00m
Southwest
Wed 7/226:10 am
MDW
- SAN
Nonstop4h 10m
Southwest
Deal found 5/23![Southwest logo]()
$357
This United Airlines deal was found by Cheapflights users on 5/25. 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 10/102:24 pm
SAN
- STL
2 stops7h 21m
United Airlines
Tue 10/135:36 pm
STL
- SAN
1 stop7h 05m
United Airlines
Deal found 5/25![United Airlines logo]()
$402
This Delta deal was found by Cheapflights users on 5/24. 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 7/76:15 am
SAN
- MDW
1 stop8h 00m
Delta
Fri 7/107:06 pm
MDW
- SAN
1 stop6h 24m
Delta
Deal found 5/24![Delta logo]()
$376
This KAYAK deal was found by Cheapflights users on 5/22. 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.
Mon 6/81:19 pm
SAN
- ORD
Nonstop4h 26m
American Airlines
Sat 6/135:00 am
ORD
- SAN
1 stop7h 09m
American Airlines
Deal found 5/22![American Airlines logo]()
$388
This Kiwi.com deal was found by Cheapflights users on 5/26. 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 7/304:12 pm
SAN
- RFD
1 stop26h 11m
Multiple Airlines
Mon 8/39:13 pm
RFD
- SAN
1 stop20h 14m
Multiple Airlines
Deal found 5/26![Multiple Airlines logo]()
$355
Last-minute flights from San Diego to IllinoisDiscover last-minute flight deals from San Diego to Illinois. Data last updated May 27, 2026 and is based on user searches.
Discover last-minute flight deals from San Diego to Illinois. Data last updated May 27, 2026 and is based on user searches.
This Expedia deal was found by Cheapflights users on 5/26. 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 6/26:25 am
SAN
- STL
1 stop6h 23m
Frontier
Tue 6/98:08 pm
STL
- SAN
1 stop5h 45m
Frontier
Deal found 5/26![Frontier logo]()
$253
This Trip.com deal was found by Cheapflights users on 5/24. 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 6/76:25 am
SAN
- STL
1 stop10h 58m
Frontier
Wed 6/107:03 pm
STL
- SAN
1 stop15h 45m
Frontier
Deal found 5/24![Frontier logo]()
$216
This Frontier deal was found by Cheapflights users on 5/24. 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.
Mon 6/86:25 am
SAN
- STL
1 stop10h 58m
Frontier
Fri 6/127:38 pm
STL
- SAN
1 stop6h 15m
Frontier
Deal found 5/24![Frontier logo]()
$249
This Super.com deal was found by Cheapflights users on 5/24. 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.
Tue 6/97:30 am
SAN
- STL
1 stop9h 04m
Frontier
Thu 6/117:38 pm
STL
- SAN
1 stop15h 31m
Frontier
Deal found 5/24![Frontier logo]()
$204
This Trip.com deal was found by Cheapflights users on 5/26. 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 6/97:30 am
SAN
- STL
1 stop9h 04m
Frontier
Wed 6/107:03 pm
STL
- SAN
1 stop15h 45m
Frontier
Deal found 5/26![Frontier logo]()
$210
This Expedia deal was found by Cheapflights users on 5/26. 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 6/97:30 am
SAN
- STL
1 stop9h 04m
Frontier
Mon 6/152:56 pm
STL
- SAN
1 stop19h 52m
Frontier
Deal found 5/26![Frontier logo]()
$228
This Expedia deal was found by Cheapflights users on 5/26. 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 6/116:25 am
SAN
- STL
1 stop9h 53m
Frontier
Tue 6/167:46 pm
STL
- SAN
1 stop15h 02m
Frontier
Deal found 5/26![Frontier logo]()
$198
This Super.com deal was found by Cheapflights users on 5/23. 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.
Mon 6/1510:04 am
SAN
- STL
1 stop6h 49m
Frontier
Wed 6/177:46 pm
STL
- SAN
1 stop15h 02m
Frontier
Deal found 5/23![Frontier logo]()
$256
This Trip.com deal was found by Cheapflights users on 5/23. 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 6/169:43 am
SAN
- STL
1 stop7h 08m
Frontier
Wed 6/177:46 pm
STL
- SAN
1 stop15h 02m
Frontier
Deal found 5/23![Frontier logo]()
$211
This Priceline deal was found by Cheapflights users on 5/25. 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.
Fri 6/196:25 am
SAN
- STL
1 stop10h 28m
Frontier
Tue 6/308:08 pm
STL
- SAN
1 stop5h 45m
Frontier
Deal found 5/25![Frontier logo]()
$254
This Frontier deal was found by Cheapflights users on 5/26. 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.
Sat 6/206:25 am
SAN
- STL
1 stop10h 09m
Frontier
Sat 6/272:56 pm
STL
- SAN
1 stop19h 52m
Frontier
Deal found 5/26![Frontier logo]()
$251
This Frontier deal was found by Cheapflights users on 5/25. 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.
Mon 6/296:25 am
SAN
- ORD
1 stop12h 18m
Frontier
Thu 7/29:48 pm
ORD
- SAN
1 stop13h 21m
Frontier
Deal found 5/25![Frontier logo]()
$258
One-way flights from San Diego to IllinoisSearch for one-way flight options from San Diego to Illinois. Find affordable one-way fares based on user searches. Data last updated May 27, 2026.
Search for one-way flight options from San Diego to Illinois. Find affordable one-way fares based on user searches. Data last updated May 27, 2026.
This Frontier deal was found by Cheapflights users on 5/25. 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.
Mon 6/89:43 am
SAN
- STL
1 stop8h 28m
Frontier
Deal found 5/25![Frontier logo]()
$99
This Frontier deal was found by Cheapflights users on 5/25. 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 6/97:30 am
SAN
- STL
1 stop9h 04m
Frontier
Deal found 5/25![Frontier logo]()
$100
This Super.com deal was found by Cheapflights users on 5/24. 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.
Sun 6/76:25 am
SAN
- STL
1 stop10h 58m
Frontier
Deal found 5/24![Frontier logo]()
$104
This Priceline deal was found by Cheapflights users on 5/26. 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.
Thu 6/186:25 am
SAN
- STL
1 stop10h 28m
Frontier
Deal found 5/26![Frontier logo]()
$105
This Jettzy deal was found by Cheapflights users on 5/25. 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 Jettzy is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/156:25 am
SAN
- STL
1 stop10h 28m
Frontier
Deal found 5/25![Frontier logo]()
$106
This Mytrip deal was found by Cheapflights users on 5/23. 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.
Sun 8/28:51 pm
SAN
- STL
1 stop19h 24m
Frontier
Deal found 5/23![Frontier logo]()
$110
This Frontier deal was found by Cheapflights users on 5/26. 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.
Fri 8/1410:00 am
SAN
- STL
1 stop7h 23m
Frontier
Deal found 5/26![Frontier logo]()
$129
This Frontier deal was found by Cheapflights users on 5/24. 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 9/308:32 pm
SAN
- ORD
1 stop11h 29m
Frontier
Deal found 5/24![Frontier logo]()
$130
This Super.com deal was found by Cheapflights users on 5/26. 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.
Wed 7/223:03 pm
SAN
- STL
1 stop25h 12m
Frontier
Deal found 5/26![Frontier logo]()
$130
This Super.com deal was found by Cheapflights users on 5/23. 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.
Mon 6/1510:04 am
SAN
- ORD
1 stop8h 39m
Frontier
Deal found 5/23![Frontier logo]()
$133
This Super.com deal was found by Cheapflights users on 5/23. 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.
Sat 6/136:25 am
SAN
- MDW
1 stop6h 50m
Frontier
Deal found 5/23![Frontier logo]()
$133
This Super.com deal was found by Cheapflights users on 5/26. 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.
Sat 6/276:25 am
SAN
- STL
1 stop10h 28m
Frontier
Deal found 5/26![Frontier logo]()
$133
Find flight deals from San Diego to Illinois
Keep the following information in mind while searching for San Diego to Illinois flight deals. Data was last updated May 27, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $198 (Expedia) |
One-way from | $99 (Frontier) |
Popular in | June |
Cheapest in | February |
Average price | $298 |
Good round-trip deal | $354 or less |
Good one-way deal | $181 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from San Diego 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 May 27, 2026.
Use the filters below to find and compare flights from San Diego to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
San DiegoChicago
SAN - RFD
SANRFD
San Diego
Tue 7/14
4:12 pm-7:59 pm
1 stop25h 47m
Chicago Greater Rockford
Fri 7/17
9:13 pm-3:27 pm
1 stop20h 14m
$278
San DiegoChicago
SAN - RFD
SANRFD
San Diego
Wed 7/22
4:38 pm-12:24 pm
2 stops17h 46m
Chicago Greater Rockford
Mon 7/27
9:13 pm-3:27 pm
1 stop20h 14m
$288
San DiegoSt. Louis
SAN - STL
SANSTL
San Diego
Fri 6/19
2:31 pm-11:56 pm
1 stop7h 25m
Lambert-St Louis
Fri 6/26
5:36 pm-11:35 pm
1 stop7h 59m
$297
San DiegoChicago
SAN - RFD
SANRFD
San Diego
Wed 7/8
3:03 pm-12:24 pm
1 stop19h 21m
Chicago Greater Rockford
Sat 7/18
12:58 pm-3:27 pm
1 stop28h 29m
$305
San DiegoChicago
SAN - RFD
SANRFD
San Diego
Thu 9/17
7:24 pm-6:11 pm
1 stop20h 47m
Chicago Greater Rockford
Mon 9/21
8:44 pm-9:02 am
1 stop14h 18m
$314
San DiegoChicago
SAN - RFD
SANRFD
San Diego
Thu 8/20
4:17 pm-12:23 pm
1 stop18h 06m
Chicago Greater Rockford
Sun 8/23
9:35 pm-8:58 pm
1 stop25h 23m
$314
San DiegoChicago
SAN - ORD
SANORD
San Diego
Wed 6/10
5:23 pm-11:36 pm
Nonstop4h 13m
Chicago O'Hare Intl
Sat 6/13
6:20 am-8:54 am
Nonstop4h 34m
$317
San DiegoChicago
SAN - ORD
SANORD
San Diego
Tue 6/9
10:55 am-8:11 pm
1 stop7h 16m
Chicago O'Hare Intl
Thu 6/11
8:10 pm-10:39 pm
Nonstop4h 29m
$327
San DiegoChicago
SAN - MDW
SANMDW
San Diego
Wed 10/7
10:30 pm-8:45 am
1 stop8h 15m
Chicago Midway
Sat 10/10
5:25 pm-11:03 pm
1 stop7h 38m
$327
Quickest round-trip
San DiegoChicago
SAN - MDW
SANMDW
San Diego
Fri 8/14
10:40 pm-4:30 am
Nonstop3h 50m
Chicago Midway
Wed 8/19
8:25 pm-10:35 pm
Nonstop4h 10m
$332
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from San Diego to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from San Diego with our price prediction graph.
SAN-STL
SAN-ORD
SAN-MDW
SAN-RFD
SAN-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 Diego to Illinois
SAN-USIL
SAN-STL
SAN-ORD
SAN-MDW
SAN-RFD
What is the cheapest month to book a flight from San Diego to Illinois?
Currently, February is the cheapest month in which you can book a flight from San Diego to Illinois (average of $91). Flying from San Diego to Illinois in April is currently the most expensive (average of $748). 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 SAN to IL?
Find hourly flight availability from San Diego 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 May 27, 2026.
When flying from San Diego to Illinois, the time of day you fly usually plays a role in the price. Save by searching for a flight in the afternoon, which can drop the price by up to 29% versus a flight in the morning.
Weekly flight availability from San Diego to Illinois
Explore weekly flight availability from San Diego 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 May 27, 2026.
The most flights from SAN to USIL are scheduled on a Monday (51 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (35 on average).
How much does it cost to fly round-trip from San Diego to Illinois?
How far ahead should I book a flight from San Diego to Illinois?
To ensure you get the cheapest price possible for a flight from San Diego to Illinois, you should look to book at least 34 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.
What is the cheapest day to fly from San Diego to Illinois?
Use this chart to determine the cheapest time to fly round-trip from San Diego to Illinois. Price data was last updated on May 23, 2026.
Travelers seeking maximum savings on their San Diego to Illinois flight should consider departing on Wednesday 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.
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 May 27, 2026.
Read reviews from past customers who have flown Alaska Airlines,Southwest, andUnited Airlines from San Diego to Illinois. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Boarding
8.1
Comfort
7.8
Entertainment
7.0
Overall
7.9
Food
7.1
Crew
8.5
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Boarding
8.1
Comfort
7.8
Entertainment
7.0
Overall
7.9
Food
7.1
Crew
8.5
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Boarding
8.1
Comfort
7.8
Entertainment
7.0
Overall
7.9
Food
7.1
Crew
8.5
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Boarding
8.1
Comfort
7.8
Entertainment
7.0
Overall
7.9
Food
7.1
Crew
8.5
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Boarding
8.1
Comfort
7.8
Entertainment
7.0
Overall
7.9
Food
7.1
Crew
8.5
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Boarding
8.1
Comfort
7.8
Entertainment
7.0
Overall
7.9
Food
7.1
Crew
8.5
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Related info for your journey
Find useful and relevant information for your journey from San Diego 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 Diego to Illinois
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Complete your trip
Complete your trip to Illinois by adding a car rental and/or hotel reservation to your travel itinerary.
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Find flights from San Diego to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
San Diego and Illinois flights
Browse other San Diego and Illinois flight options. Last updated on May 27, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
San Diego to Illinois flights
Consider these flights traveling from San Diego to Illinois.
Top 6 airlines flying from San Diego to Illinois
Discover the top 6 airlines that operate flights from San Diego 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 May 27, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$51 | Average$233 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$139 | Average$197 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$153 | Average$302 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$157 | Average$448 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$167 | Average$426 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$205 | Average$352 | FlexibilityNo cancel fee | On-time63% |