$94+ 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 8/19. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — ORD
Aug 20 — Aug 271
Round-trip
1 adult, Economy
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Find cheap flights from San Diego to Illinois with Cheapflights
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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 July 21, 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 July 21, 2026.
This Alaska Airlines deal was found by Cheapflights users on 7/20. 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 9/176:55 am
SAN
- STL
1 stop8h 15m
Alaska Airlines
Wed 9/236:29 am
STL
- SAN
1 stop10h 13m
Alaska Airlines
Deal found 7/20![Alaska Airlines logo]()
$187
This Booking.com deal was found by Cheapflights users on 7/20. 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.
Sat 8/296:55 am
SAN
- STL
1 stop8h 15m
Multiple Airlines
Wed 9/26:45 pm
STL
- SAN
1 stop27h 29m
Multiple Airlines
Deal found 7/20![Multiple Airlines logo]()
$224
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 9/23:45 pm
SAN
- STL
1 stop25h 28m
Frontier
Wed 9/910:35 am
STL
- SAN
2 stops31h 06m
Frontier
Deal found 7/20![Frontier logo]()
$225
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 9/176:55 am
SAN
- STL
1 stop8h 15m
Multiple Airlines
Mon 9/218:10 pm
STL
- SAN
1 stop5h 49m
Multiple Airlines
Deal found 7/20![Multiple Airlines logo]()
$226
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 9/176:55 am
SAN
- STL
1 stop8h 15m
Multiple Airlines
Fri 9/2512:46 pm
STL
- SAN
1 stop10h 02m
Multiple Airlines
Deal found 7/20![Multiple Airlines logo]()
$229
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 9/1710:36 am
SAN
- STL
1 stop6h 39m
Frontier
Wed 9/2310:35 am
STL
- SAN
2 stops25h 06m
Frontier
Deal found 7/20![Frontier logo]()
$236
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 9/1710:36 am
SAN
- STL
1 stop6h 39m
Frontier
Thu 9/2410:35 am
STL
- SAN
2 stops25h 06m
Frontier
Deal found 7/20![Frontier logo]()
$237
This Expedia deal was found by Cheapflights users on 7/20. 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 8/113:03 pm
SAN
- STL
1 stop25h 02m
Frontier
Thu 8/138:08 pm
STL
- SAN
1 stop5h 43m
Frontier
Deal found 7/20![Frontier logo]()
$240
This Kiwi.com deal was found by Cheapflights users on 7/20. 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.
Sat 8/293:45 pm
SAN
- STL
2 stops23h 37m
Frontier
Wed 9/26:45 pm
STL
- SAN
1 stop27h 29m
Frontier
Deal found 7/20![Frontier logo]()
$245
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 9/176:55 am
SAN
- STL
1 stop8h 15m
Multiple Airlines
Sun 9/2012:46 pm
STL
- SAN
1 stop10h 02m
Multiple Airlines
Deal found 7/20![Multiple Airlines logo]()
$247
This Kiwi.com deal was found by Cheapflights users on 7/20. 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.
Sat 9/126:55 am
SAN
- STL
1 stop8h 15m
Multiple Airlines
Sat 9/1912:46 pm
STL
- SAN
1 stop25h 39m
Multiple Airlines
Deal found 7/20![Multiple Airlines logo]()
$248
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 9/178:32 pm
SAN
- STL
2 stops35h 08m
Frontier
Mon 9/218:10 pm
STL
- SAN
1 stop5h 49m
Frontier
Deal found 7/20![Frontier logo]()
$249
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 July 21, 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 July 21, 2026.
This CheapOair deal was found by Cheapflights users on 7/20. 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.
Sat 10/2412:10 pm
SAN
- STL
1 stop9h 49m
Alaska Airlines
Sat 10/316:02 am
STL
- SAN
1 stop10h 36m
Alaska Airlines
Deal found 7/20![Alaska Airlines logo]()
$283
This Southwest deal was found by Cheapflights users on 7/20. 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 10/1510:40 pm
SAN
- MDW
Nonstop3h 50m
Southwest
Sun 10/186:30 am
MDW
- SAN
Nonstop4h 25m
Southwest
Deal found 7/20![Southwest logo]()
$287
This Kiwi.com deal was found by Cheapflights users on 7/19. 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 8/276:25 am
SAN
- RFD
2 stops12h 20m
Multiple Airlines
Sun 8/309:35 pm
RFD
- SAN
1 stop24h 39m
Multiple Airlines
Deal found 7/19![Multiple Airlines logo]()
$287
This Delta deal was found by Cheapflights users on 7/19. 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 8/149:30 pm
SAN
- STL
1 stop9h 50m
Delta
Tue 8/1812:52 pm
STL
- SAN
1 stop8h 43m
Delta
Deal found 7/19![Delta logo]()
$297
This United Airlines deal was found by Cheapflights users on 7/17. 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 8/1110:40 pm
SAN
- ORD
Nonstop4h 03m
United Airlines
Thu 8/135:00 am
ORD
- SAN
1 stop6h 05m
United Airlines
Deal found 7/17![United Airlines logo]()
$301
This Frontier deal was found by Cheapflights users on 7/15. 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 7/258:51 pm
SAN
- ORD
1 stop6h 46m
Frontier
Tue 7/289:57 pm
ORD
- SAN
1 stop13h 08m
Frontier
Deal found 7/15![Frontier logo]()
$352
This American Airlines deal was found by Cheapflights users on 7/16. 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 11/117:53 am
SAN
- EVV
1 stop8h 38m
American Airlines
Wed 11/255:10 am
EVV
- SAN
1 stop8h 01m
American Airlines
Deal found 7/16![American Airlines logo]()
$419
This Southwest deal was found by Cheapflights users on 7/17. 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 9/296:55 am
SAN
- MDW
Nonstop4h 00m
Southwest
Sat 10/311:25 am
MDW
- SAN
2 stops7h 45m
Southwest
Deal found 7/17![Southwest logo]()
$292
This Alaska Airlines deal was found by Cheapflights users on 7/20. 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 8/251:03 pm
SAN
- ORD
Nonstop4h 18m
Alaska Airlines
Tue 9/16:00 am
ORD
- SAN
1 stop10h 44m
Alaska Airlines
Deal found 7/20![Alaska Airlines logo]()
$294
This Delta deal was found by Cheapflights users on 7/18. 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 9/16:15 am
SAN
- STL
1 stop10h 12m
Delta
Thu 9/36:30 am
STL
- SAN
1 stop9h 40m
Delta
Deal found 7/18![Delta logo]()
$297
This Kiwi.com deal was found by Cheapflights users on 7/16. 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 9/2412:37 pm
SAN
- RFD
2 stops18h 15m
Multiple Airlines
Mon 9/288:44 pm
RFD
- SAN
1 stop14h 18m
Multiple Airlines
Deal found 7/16![Multiple Airlines logo]()
$301
This United Airlines deal was found by Cheapflights users on 7/15. 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 10/711:00 am
SAN
- ORD
1 stop6h 29m
United Airlines
Mon 10/127:05 am
ORD
- SAN
Nonstop4h 27m
United Airlines
Deal found 7/15![United Airlines logo]()
$302
This Alaska Airlines deal was found by Cheapflights users on 7/19. 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 9/21:03 pm
SAN
- ORD
Nonstop4h 18m
Alaska Airlines
Wed 9/98:00 am
ORD
- SAN
1 stop11h 13m
Alaska Airlines
Deal found 7/19![Alaska Airlines logo]()
$294
This Southwest deal was found by Cheapflights users on 7/19. 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 8/193:15 pm
SAN
- MDW
1 stop5h 35m
Southwest
Tue 8/2510:30 am
MDW
- SAN
2 stops6h 55m
Southwest
Deal found 7/19![Southwest logo]()
$302
This Delta deal was found by Cheapflights users on 7/20. 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.
Sat 10/247:20 am
SAN
- STL
2 stops11h 39m
Delta
Sat 10/3111:10 am
STL
- SAN
2 stops13h 41m
Delta
Deal found 7/20![Delta logo]()
$303
This Kiwi.com deal was found by Cheapflights users on 7/18. 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 10/87:13 pm
SAN
- RFD
1 stop14h 14m
Multiple Airlines
Wed 10/142:07 pm
RFD
- SAN
2 stops21h 13m
Multiple Airlines
Deal found 7/18![Multiple Airlines logo]()
$318
This Southwest deal was found by Cheapflights users on 7/18. 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 9/145:50 pm
SAN
- MDW
Nonstop3h 55m
Southwest
Fri 9/182:50 pm
MDW
- SAN
Nonstop4h 05m
Southwest
Deal found 7/18![Southwest logo]()
$304
This United Airlines deal was found by Cheapflights users on 7/21. 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 8/196:40 am
SAN
- PIA
1 stop6h 17m
United Airlines
Tue 8/255:45 am
PIA
- SAN
2 stops11h 05m
United Airlines
Deal found 7/21![United Airlines logo]()
$340
This Delta deal was found by Cheapflights users on 7/17. 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.
Mon 8/1010:17 pm
SAN
- ORD
1 stop7h 39m
Delta
Thu 8/139:54 am
ORD
- SAN
1 stop9h 10m
Delta
Deal found 7/17![Delta logo]()
$311
This Alaska Airlines deal was found by Cheapflights users on 7/17. 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 9/169:31 am
SAN
- ORD
1 stop12h 28m
Alaska Airlines
Thu 9/178:00 am
ORD
- SAN
1 stop11h 13m
Alaska Airlines
Deal found 7/17![Alaska Airlines logo]()
$311
This Expedia deal was found by Cheapflights users on 7/15. 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 8/38:51 pm
SAN
- ORD
1 stop6h 46m
Multiple Airlines
Mon 8/108:20 pm
ORD
- SAN
1 stop14h 50m
Multiple Airlines
Deal found 7/15![Multiple Airlines logo]()
$338
This Southwest deal was found by Cheapflights users on 7/15. 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 8/1910:40 pm
SAN
- MDW
1 stop6h 30m
Southwest
Mon 8/249:00 am
MDW
- SAN
2 stops11h 10m
Southwest
Deal found 7/15![Southwest logo]()
$308
This United Airlines deal was found by Cheapflights users on 7/16. 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 8/2811:20 am
SAN
- PIA
2 stops9h 23m
United Airlines
Sat 9/58:45 am
PIA
- SAN
1 stop8h 05m
United Airlines
Deal found 7/16![United Airlines logo]()
$340
This Delta deal was found by Cheapflights users on 7/20. 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.
Mon 8/1010:17 pm
SAN
- MDW
1 stop9h 00m
Delta
Thu 8/1312:46 pm
MDW
- SAN
1 stop8h 49m
Delta
Deal found 7/20![Delta logo]()
$321
This American Airlines deal was found by Cheapflights users on 7/20. 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 9/51:38 pm
SAN
- PIA
1 stop7h 41m
American Airlines
Mon 9/76:48 pm
PIA
- SAN
1 stop6h 59m
American Airlines
Deal found 7/20![American Airlines logo]()
$429
This Kiwi.com deal was found by Cheapflights users on 7/19. 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 8/206:25 am
SAN
- RFD
1 stop27h 58m
Multiple Airlines
Mon 8/241:13 pm
RFD
- SAN
1 stop12h 31m
Multiple Airlines
Deal found 7/19![Multiple Airlines logo]()
$340
This Southwest deal was found by Cheapflights users on 7/18. 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 9/196:20 am
SAN
- MDW
2 stops8h 45m
Southwest
Sat 9/196:05 pm
MDW
- SAN
Nonstop4h 15m
Southwest
Deal found 7/18![Southwest logo]()
$312
This Alaska Airlines deal was found by Cheapflights users on 7/19. 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 7/287:00 am
SAN
- ORD
Nonstop4h 21m
Alaska Airlines
Tue 8/117:59 pm
ORD
- SAN
Nonstop4h 34m
Alaska Airlines
Deal found 7/19![Alaska Airlines logo]()
$349
This American Airlines deal was found by Cheapflights users on 7/17. 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 10/289:57 am
SAN
- BMI
2 stops11h 01m
American Airlines
Sun 11/12:30 pm
BMI
- SAN
1 stop6h 58m
American Airlines
Deal found 7/17![American Airlines logo]()
$441
This Southwest deal was found by Cheapflights users on 7/16. 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 9/1710:40 pm
SAN
- MDW
Nonstop3h 50m
Southwest
Sun 9/206:10 am
MDW
- SAN
Nonstop4h 10m
Southwest
Deal found 7/16![Southwest logo]()
$317
Last-minute flights from San Diego to IllinoisDiscover last-minute flight deals from San Diego to Illinois. Data last updated July 21, 2026 and is based on user searches.
Discover last-minute flight deals from San Diego to Illinois. Data last updated July 21, 2026 and is based on user searches.
This CheapOair deal was found by Cheapflights users on 7/20. 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.
Mon 8/38:51 pm
SAN
- STL
1 stop19h 14m
Frontier
Wed 8/57:03 pm
STL
- SAN
1 stop27h 03m
Frontier
Deal found 7/20![Frontier logo]()
$264
This Super.com deal was found by Cheapflights users on 7/19. 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 8/43:03 pm
SAN
- STL
1 stop25h 02m
Frontier
Thu 8/138:08 pm
STL
- SAN
1 stop5h 43m
Frontier
Deal found 7/19![Frontier logo]()
$260
This deal was found by Cheapflights users on 7/18. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/510:10 am
SAN
- STL
1 stop7h 13m
Frontier
Thu 8/138:08 pm
STL
- SAN
1 stop5h 43m
Frontier
Deal found 7/18![Frontier logo]()
$268
This Kiwi.com deal was found by Cheapflights users on 7/16. 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 8/76:25 am
SAN
- STL
1 stop10h 58m
Frontier
Mon 8/108:08 pm
STL
- SAN
2 stops20h 00m
Frontier
Deal found 7/16![Frontier logo]()
$261
This Expedia deal was found by Cheapflights users on 7/20. 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 8/113:03 pm
SAN
- STL
1 stop25h 02m
Frontier
Thu 8/138:08 pm
STL
- SAN
1 stop5h 43m
Frontier
Deal found 7/20![Frontier logo]()
$240
This Expedia deal was found by Cheapflights users on 7/19. 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.
Sat 8/158:51 pm
SAN
- STL
1 stop19h 24m
Multiple Airlines
Thu 8/206:08 pm
STL
- SAN
1 stop18h 22m
Multiple Airlines
Deal found 7/19![Multiple Airlines logo]()
$269
This Expedia deal was found by Cheapflights users on 7/20. 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 8/178:51 pm
SAN
- STL
1 stop18h 59m
Multiple Airlines
Mon 9/217:36 pm
STL
- SAN
1 stop17h 10m
Multiple Airlines
Deal found 7/20![Multiple Airlines logo]()
$225
This Kiwi.com deal was found by Cheapflights users on 7/18. 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 8/176:25 am
SAN
- STL
1 stop10h 58m
Frontier
Thu 8/206:17 pm
STL
- SAN
2 stops40h 48m
Frontier
Deal found 7/18![Frontier logo]()
$263
This Kiwi.com deal was found by Cheapflights users on 7/15. 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 8/263:45 pm
SAN
- STL
1 stop25h 28m
Frontier
Tue 9/15:27 pm
STL
- SAN
2 stops28h 48m
Frontier
Deal found 7/15![Frontier logo]()
$259
This CheapOair deal was found by Cheapflights users on 7/20. 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 8/286:55 am
SAN
- STL
1 stop8h 15m
Alaska Airlines
Sun 9/66:08 pm
STL
- SAN
1 stop18h 22m
Alaska Airlines
Deal found 7/20![Alaska Airlines logo]()
$207
This Booking.com deal was found by Cheapflights users on 7/20. 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.
Sat 8/296:55 am
SAN
- STL
1 stop8h 15m
Multiple Airlines
Wed 9/26:45 pm
STL
- SAN
1 stop27h 29m
Multiple Airlines
Deal found 7/20![Multiple Airlines logo]()
$224
This Kiwi.com deal was found by Cheapflights users on 7/20. 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.
Sat 8/293:45 pm
SAN
- STL
2 stops23h 37m
Frontier
Wed 9/26:45 pm
STL
- SAN
1 stop27h 29m
Frontier
Deal found 7/20![Frontier logo]()
$245
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 July 21, 2026.
Search for one-way flight options from San Diego to Illinois. Find affordable one-way fares based on user searches. Data last updated July 21, 2026.
This Alaska Airlines deal was found by Cheapflights users on 7/19. 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 8/196:55 am
SAN
- STL
1 stop8h 15m
Alaska Airlines
Deal found 7/19![Alaska Airlines logo]()
$94
This Alaska Airlines deal was found by Cheapflights users on 7/16. 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 9/148:06 pm
SAN
- STL
1 stop19h 04m
Alaska Airlines
Deal found 7/16![Alaska Airlines logo]()
$99
This Kiwi.com deal was found by Cheapflights users on 7/17. 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 8/193:45 pm
SAN
- STL
1 stop25h 28m
Frontier
Deal found 7/17![Frontier logo]()
$102
This Kiwi.com deal was found by Cheapflights users on 7/16. 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 10/136:25 am
SAN
- STL
1 stop10h 50m
Frontier
Deal found 7/16![Frontier logo]()
$103
This Alaska Airlines deal was found by Cheapflights users on 7/17. 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 9/186:55 am
SAN
- STL
1 stop8h 15m
Alaska Airlines
Deal found 7/17![Alaska Airlines logo]()
$104
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 9/166:25 am
SAN
- STL
2 stops25h 15m
Frontier
Deal found 7/20![Frontier logo]()
$109
This Kiwi.com deal was found by Cheapflights users on 7/19. 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 10/206:25 am
SAN
- STL
2 stops25h 15m
Frontier
Deal found 7/19![Frontier logo]()
$111
This Kiwi.com deal was found by Cheapflights users on 7/17. 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 9/146:25 am
SAN
- STL
1 stop10h 50m
Frontier
Deal found 7/17![Frontier logo]()
$112
This Kiwi.com deal was found by Cheapflights users on 7/16. 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 10/126:25 am
SAN
- STL
1 stop10h 50m
Frontier
Deal found 7/16![Frontier logo]()
$115
This Kiwi.com deal was found by Cheapflights users on 7/16. 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 8/54:45 pm
SAN
- MLI
1 stop18h 18m
Multiple Airlines
Deal found 7/16![Multiple Airlines logo]()
$115
This Super.com deal was found by Cheapflights users on 7/17. 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.
Fri 8/710:10 am
SAN
- STL
1 stop7h 13m
Frontier
Deal found 7/17![Frontier logo]()
$118
This Super.com deal was found by Cheapflights users on 7/17. 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 8/166:35 am
SAN
- STL
1 stop6h 21m
Frontier
Deal found 7/17![Frontier logo]()
$119
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 July 21, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $187 (Travelocity) |
One-way from | $94 (Alaska Airlines) |
Popular in | June |
Cheapest in | February |
Average price | $357 |
Good round-trip deal | $335 or less |
Good one-way deal | $195 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 July 21, 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 DiegoSt. Louis
SAN - STL
SANSTL
San Diego
Sat 10/24
12:10 pm-11:59 pm
1 stop9h 49m
Lambert-St Louis
Sat 10/31
6:02 am-2:38 pm
1 stop10h 36m
$283
San DiegoChicago
SAN - MDW
SANMDW
San Diego
Thu 10/15
10:40 pm-4:30 am
Nonstop3h 50m
Chicago Midway
Sun 10/18
6:30 am-8:55 am
Nonstop4h 25m
$287
San DiegoChicago
SAN - RFD
SANRFD
San Diego
Thu 8/27
6:25 am-8:45 pm
2 stops12h 20m
Chicago Greater Rockford
Sun 8/30
9:35 pm-8:14 pm
1 stop24h 39m
$287
San DiegoChicago
SAN - MDW
SANMDW
San Diego
Tue 9/29
6:55 am-12:55 pm
Nonstop4h 00m
Chicago Midway
Sat 10/3
11:25 am-5:10 pm
2 stops7h 45m
$292
San DiegoChicago
SAN - ORD
SANORD
San Diego
Tue 8/25
1:03 pm-7:21 pm
Nonstop4h 18m
Chicago O'Hare Intl
Tue 9/1
6:00 am-2:44 pm
1 stop10h 44m
$294
San DiegoChicago
SAN - ORD
SANORD
San Diego
Wed 9/2
1:03 pm-7:21 pm
Nonstop4h 18m
Chicago O'Hare Intl
Wed 9/9
8:00 am-5:13 pm
1 stop11h 13m
$294
San DiegoSt. Louis
SAN - STL
SANSTL
San Diego
Fri 8/14
9:30 pm-9:20 am
1 stop9h 50m
Lambert-St Louis
Tue 8/18
12:52 pm-7:35 pm
1 stop8h 43m
$297
San DiegoSt. Louis
SAN - STL
SANSTL
San Diego
Tue 9/1
6:15 am-6:27 pm
1 stop10h 12m
Lambert-St Louis
Thu 9/3
6:30 am-2:10 pm
1 stop9h 40m
$297
San DiegoChicago
SAN - ORD
SANORD
San Diego
Tue 8/11
10:40 pm-4:43 am
Nonstop4h 03m
Chicago O'Hare Intl
Thu 8/13
5:00 am-9:05 am
1 stop6h 05m
$301
San DiegoChicago
SAN - RFD
SANRFD
San Diego
Thu 9/24
12:37 pm-8:52 am
2 stops18h 15m
Chicago Greater Rockford
Mon 9/28
8:44 pm-9:02 am
1 stop14h 18m
$301
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-MDW
SAN-RFD
SAN-ORD
SAN-EVV
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-MDW
SAN-RFD
SAN-ORD
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 $254). Flying from San Diego to Illinois in July is currently the most expensive (average of $375). 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 July 21, 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 21% 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 July 21, 2026.
The most flights from SAN to USIL are scheduled on a Monday (52 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (47 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 90 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 July 18, 2026.
Travelers seeking maximum savings on their San Diego to Illinois flight should consider departing on Sunday 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 July 21, 2026.
Read reviews from past customers who have flown Southwest,Alaska Airlines, andUnited Airlines from San Diego to Illinois. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Comfort
8.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
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 July 21, 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 July 21, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$115 | Average$250 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$137 | Average$181 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$156 | Average$321 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$157 | Average$462 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$163 | Average$417 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$205 | Average$371 | FlexibilityNo cancel fee | On-time63% |