$159+ Cheap flights from Seattle (SEA) to Illinois
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/23. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ORD
Nov 24 — Dec 11
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to Illinois with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
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Cheapest flights from Seattle to IllinoisExplore the most affordable flight options available from Seattle to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 25, 2026.
Explore the most affordable flight options available from Seattle to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 25, 2026.
This Mytrip deal was found by Cheapflights users on 10/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/184:27 pm -
2 stops15h 00m
Tue 12/11:19 pm -
2 stops28h 21m
Deal found 10/20![Frontier logo]()
$280
This Kiwi.com deal was found by Cheapflights users on 10/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/144:27 pm -
1 stop5h 54m
Thu 11/195:15 pm -
1 stop21h 22m
Deal found 10/21![Frontier logo]()
$281
This Mytrip deal was found by Cheapflights users on 10/21. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/184:27 pm -
1 stop5h 54m
Wed 11/2510:00 pm -
2 stops19h 22m
Deal found 10/21![Frontier logo]()
$282
This Cheapflightsfares deal was found by Cheapflights users on 10/22. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/39:07 pm -
1 stop29h 52m
Mon 12/77:25 am -
1 stop10h 18m
Deal found 10/22![Frontier logo]()
$283
This Booking.com deal was found by Cheapflights users on 10/22. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/239:53 pm -
1 stop29h 17m
Tue 12/85:29 pm -
Nonstop4h 59m
Deal found 10/22![Multiple Airlines logo]()
$284
This Expedia deal was found by Cheapflights users on 10/21. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/229:53 pm -
1 stop29h 17m
Wed 11/256:54 pm -
Nonstop5h 02m
Deal found 10/21![Multiple Airlines logo]()
$285
This Kiwi.com deal was found by Cheapflights users on 10/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/134:27 pm -
1 stop5h 54m
Sat 11/215:15 am -
1 stop9h 22m
Deal found 10/21![Frontier logo]()
$286
This Orbitz deal was found by Cheapflights users on 10/23. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/94:27 pm -
1 stop5h 54m
Thu 11/127:20 am -
1 stop9h 25m
Deal found 10/23![Multiple Airlines logo]()
$287
This Southwest deal was found by Cheapflights users on 10/23. 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.
Mon 12/76:30 am -
Nonstop3h 55m
Fri 12/119:45 pm -
Nonstop4h 50m
Deal found 10/23![Southwest logo]()
$287
This Alaska Airlines deal was found by Cheapflights users on 10/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/148:44 am -
Nonstop4h 16m
Sat 11/146:35 pm -
Nonstop4h 54m
Deal found 10/21![Alaska Airlines logo]()
$288
This Trip.com deal was found by Cheapflights users on 10/21. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/95:51 pm -
Nonstop4h 08m
Mon 11/166:35 pm -
Nonstop4h 54m
Deal found 10/21![Alaska Airlines logo]()
$289
This Cheapflightsfares deal was found by Cheapflights users on 10/21. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/229:53 pm -
1 stop29h 17m
Wed 11/2510:00 pm -
1 stop24h 38m
Deal found 10/21![Frontier logo]()
$290
Best flights from Seattle to IllinoisDiscover carefully curated flight deals from Seattle to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 25, 2026.
Discover carefully curated flight deals from Seattle to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 25, 2026.
This Alaska Airlines deal was found by Cheapflights users on 10/23. 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.
Sat 11/1411:23 am -
Nonstop4h 14m
Mon 11/166:35 pm -
Nonstop4h 54m
Deal found 10/23![Alaska Airlines logo]()
$293
This Southwest deal was found by Cheapflights users on 10/21. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/46:15 am -
Nonstop3h 55m
Mon 2/89:55 pm -
Nonstop4h 40m
Deal found 10/21![Southwest logo]()
$293
This United Airlines deal was found by Cheapflights users on 10/24. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/92:05 pm -
Nonstop4h 10m
Mon 12/217:42 pm -
Nonstop4h 50m
Deal found 10/24![United Airlines logo]()
$329
This Delta deal was found by Cheapflights users on 10/23. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/137:27 am -
Nonstop4h 10m
Tue 11/175:55 pm -
Nonstop4h 43m
Deal found 10/23![Delta logo]()
$336
This American Airlines deal was found by Cheapflights users on 10/23. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/1012:37 pm -
1 stop7h 27m
Thu 12/172:39 pm -
1 stop10h 30m
Deal found 10/23![American Airlines logo]()
$542
This Alaska Airlines deal was found by Cheapflights users on 10/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/158:09 pm -
1 stop15h 06m
Mon 12/218:59 pm -
Nonstop4h 54m
Deal found 10/21![Alaska Airlines logo]()
$303
This Southwest deal was found by Cheapflights users on 10/20. 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.
Wed 12/26:10 am -
2 stops9h 00m
Tue 12/158:45 pm -
Nonstop4h 50m
Deal found 10/20![Southwest logo]()
$308
This Southwest deal was found by Cheapflights users on 10/22. 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 12/46:30 am -
Nonstop3h 55m
Mon 12/78:45 pm -
1 stop13h 45m
Deal found 10/22![Southwest logo]()
$309
This Delta deal was found by Cheapflights users on 10/22. 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.
Wed 11/1110:39 am -
Nonstop4h 08m
Sun 11/155:55 pm -
Nonstop4h 43m
Deal found 10/22![Delta logo]()
$358
This Alaska Airlines deal was found by Cheapflights users on 10/24. 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.
Fri 11/2711:58 pm -
Nonstop3h 58m
Mon 11/309:01 pm -
1 stop14h 31m
Deal found 10/24![Alaska Airlines logo]()
$339
This Delta deal was found by Cheapflights users on 10/23. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/227:15 am -
Nonstop4h 17m
Sat 12/266:00 am -
Nonstop4h 54m
Deal found 10/23![Delta logo]()
$365
This Alaska Airlines deal was found by Cheapflights users on 10/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/2411:53 pm -
1 stop11h 17m
Sat 1/26:00 am -
Nonstop5h 00m
Deal found 10/21![Alaska Airlines logo]()
$345
This United Airlines deal was found by Cheapflights users on 10/24. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/1110:50 am -
1 stop8h 32m
Wed 11/188:13 am -
2 stops10h 14m
Deal found 10/24![United Airlines logo]()
$419
This Southwest deal was found by Cheapflights users on 10/24. 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.
Wed 12/26:10 am -
2 stops8h 55m
Mon 12/78:45 pm -
1 stop13h 45m
Deal found 10/24![Southwest logo]()
$360
This Delta deal was found by Cheapflights users on 10/20. 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.
Wed 12/210:40 pm -
1 stop9h 46m
Sat 12/56:10 am -
1 stop10h 28m
Deal found 10/20![Delta logo]()
$379
This United Airlines deal was found by Cheapflights users on 10/22. 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.
Thu 11/510:56 pm -
1 stop9h 09m
Sat 11/1410:40 am -
2 stops10h 06m
Deal found 10/22![United Airlines logo]()
$419
This Alaska Airlines deal was found by Cheapflights users on 10/19. 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.
Sun 12/135:51 pm -
Nonstop4h 08m
Wed 1/66:57 pm -
Nonstop4h 45m
Deal found 10/19![Alaska Airlines logo]()
$359
This Southwest deal was found by Cheapflights users on 10/24. 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.
Mon 12/76:10 am -
2 stops8h 55m
Sat 12/121:25 pm -
2 stops9h 05m
Deal found 10/24![Southwest logo]()
$370
This Delta deal was found by Cheapflights users on 10/20. 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.
Thu 12/175:50 pm -
Nonstop4h 07m
Sun 12/202:27 pm -
Nonstop4h 48m
Deal found 10/20![Delta logo]()
$381
This United Airlines deal was found by Cheapflights users on 10/21. 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.
Fri 11/68:35 pm -
2 stops11h 33m
Tue 11/105:30 pm -
1 stop7h 37m
Deal found 10/21![United Airlines logo]()
$435
This Southwest deal was found by Cheapflights users on 10/23. 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 11/135:30 am -
Nonstop3h 50m
Fri 11/209:45 pm -
Nonstop4h 50m
Deal found 10/23![Southwest logo]()
$384
This Delta deal was found by Cheapflights users on 10/21. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/177:27 am -
Nonstop4h 10m
Fri 11/202:32 pm -
1 stop9h 32m
Deal found 10/21![Delta logo]()
$391
This United Airlines deal was found by Cheapflights users on 10/24. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 1/97:00 am -
1 stop7h 59m
Tue 1/128:40 am -
1 stop7h 10m
Deal found 10/24![United Airlines logo]()
$441
This American Airlines deal was found by Cheapflights users on 10/22. 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 10/3010:31 am -
1 stop7h 54m
Mon 11/26:59 pm -
1 stop7h 36m
Deal found 10/22![American Airlines logo]()
$624
This Southwest deal was found by Cheapflights users on 10/24. 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.
Fri 2/56:15 am -
Nonstop3h 55m
Sun 2/79:55 pm -
Nonstop4h 40m
Deal found 10/24![Southwest logo]()
$399
This Delta deal was found by Cheapflights users on 10/21. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/1511:40 pm -
1 stop9h 46m
Thu 11/266:01 am -
1 stop8h 30m
Deal found 10/21![Delta logo]()
$399
This United Airlines deal was found by Cheapflights users on 10/23. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/77:00 am -
1 stop6h 02m
Wed 11/1110:40 am -
2 stops9h 53m
Deal found 10/23![United Airlines logo]()
$454
This American Airlines deal was found by Cheapflights users on 10/21. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/53:10 pm -
1 stop7h 00m
Thu 11/123:11 pm -
1 stop7h 09m
Deal found 10/21![American Airlines logo]()
$638
This Southwest deal was found by Cheapflights users on 10/22. 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.
Sun 11/812:15 am -
Nonstop3h 50m
Mon 11/168:45 pm -
1 stop13h 45m
Deal found 10/22![Southwest logo]()
$401
This Delta deal was found by Cheapflights users on 10/21. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/46:00 am -
2 stops14h 36m
Sat 11/146:01 am -
2 stops13h 09m
Deal found 10/21![Delta logo]()
$444
Last-minute flights from Seattle to IllinoisDiscover last-minute flight deals from Seattle to Illinois. Data last updated October 25, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Illinois. Data last updated October 25, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 10/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/24:27 pm -
1 stop5h 54m
Wed 11/116:30 am -
1 stop10h 42m
Deal found 10/23![Frontier logo]()
$291
This Orbitz deal was found by Cheapflights users on 10/23. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/94:27 pm -
1 stop5h 54m
Thu 11/127:20 am -
1 stop9h 25m
Deal found 10/23![Multiple Airlines logo]()
$287
This Trip.com deal was found by Cheapflights users on 10/21. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/95:51 pm -
Nonstop4h 08m
Mon 11/166:35 pm -
Nonstop4h 54m
Deal found 10/21![Alaska Airlines logo]()
$289
This Kiwi.com deal was found by Cheapflights users on 10/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/134:27 pm -
1 stop5h 54m
Sat 11/215:15 am -
1 stop9h 22m
Deal found 10/21![Frontier logo]()
$286
This Kiwi.com deal was found by Cheapflights users on 10/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/144:27 pm -
1 stop5h 54m
Thu 11/195:15 pm -
1 stop21h 22m
Deal found 10/21![Frontier logo]()
$281
This Alaska Airlines deal was found by Cheapflights users on 10/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/148:44 am -
Nonstop4h 16m
Sat 11/146:35 pm -
Nonstop4h 54m
Deal found 10/21![Alaska Airlines logo]()
$288
This Southwest deal was found by Cheapflights users on 10/23. 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.
Tue 11/176:30 am -
Nonstop3h 55m
Mon 11/239:45 pm -
Nonstop4h 50m
Deal found 10/23![Southwest logo]()
$291
This Mytrip deal was found by Cheapflights users on 10/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/184:27 pm -
2 stops15h 00m
Tue 12/11:19 pm -
2 stops28h 21m
Deal found 10/20![Frontier logo]()
$280
This Mytrip deal was found by Cheapflights users on 10/21. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/184:27 pm -
1 stop5h 54m
Wed 11/2510:00 pm -
2 stops19h 22m
Deal found 10/21![Frontier logo]()
$282
This Travelocity deal was found by Cheapflights users on 10/24. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/214:37 pm -
1 stop6h 16m
Wed 11/253:19 pm -
Nonstop4h 52m
Deal found 10/24![Multiple Airlines logo]()
$284
This Cheapflightsfares deal was found by Cheapflights users on 10/25. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/229:53 pm -
1 stop29h 17m
Wed 11/2510:00 pm -
1 stop24h 38m
Deal found 10/25![Frontier logo]()
$283
This Expedia deal was found by Cheapflights users on 10/21. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/229:53 pm -
1 stop29h 17m
Wed 11/256:54 pm -
Nonstop5h 02m
Deal found 10/21![Multiple Airlines logo]()
$285
One-way flights from Seattle to IllinoisSearch for one-way flight options from Seattle to Illinois. Find affordable one-way fares based on user searches. Data last updated October 25, 2026.
Search for one-way flight options from Seattle to Illinois. Find affordable one-way fares based on user searches. Data last updated October 25, 2026.
This Super.com deal was found by Cheapflights users on 10/21. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/231:37 pm -
1 stop8h 49m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/21![Frontier logo]()
$159
This Flightnetwork deal was found by Cheapflights users on 10/24. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/74:27 pm -
1 stop5h 54m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/24![Frontier logo]()
$160
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
Fri 12/41:32 pm -
2 stops20h 01m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![Frontier logo]()
$160
This Booking.com deal was found by Cheapflights users on 10/22. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/74:58 pm -
2 stops27h 02m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/22![Frontier logo]()
$161
This Southwest deal was found by Cheapflights users on 10/24. 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 12/154:40 pm -
2 stops11h 05m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/24![Southwest logo]()
$161
This Alaska Airlines deal was found by Cheapflights users on 10/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/249:59 pm -
1 stop13h 11m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/21![Alaska Airlines logo]()
$162
This Southwest deal was found by Cheapflights users on 10/20. 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.
Mon 12/218:40 pm -
1 stop9h 40m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![Southwest logo]()
$162
This Frontier deal was found by Cheapflights users on 10/20. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/181:37 pm -
1 stop8h 49m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![Frontier logo]()
$163
This Southwest deal was found by Cheapflights users on 10/20. 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.
Tue 12/17:00 am -
1 stop13h 00m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![Southwest logo]()
$163
This Kiwi.com deal was found by Cheapflights users on 10/20. 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 12/24:58 pm -
2 stops18h 33m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/20![Frontier logo]()
$164
This American Airlines deal was found by Cheapflights users on 10/24. 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.
Tue 11/245:24 pm -
Nonstop4h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/24![American Airlines logo]()
$165
This Southwest deal was found by Cheapflights users on 10/23. 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.
Sat 11/144:40 pm -
1 stop11h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/23![Southwest logo]()
$165
Find flight deals from Seattle to Illinois
Keep the following information in mind while searching for Seattle to Illinois flight deals. Data was last updated October 25, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $280 (Mytrip) |
One-way from | $159 (Super.com) |
Popular in | June |
Cheapest in | February |
Average price | $390 |
Good round-trip deal | $391 or less |
Good one-way deal | $235 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Seattle 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 7,457,451 searches. Data last updated October 25, 2026.
Use the filters below to find and compare flights from Seattle to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Thu 12/3
6:10 am-5:05 pm
2 stops8h 55m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$162
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Tue 1/12
6:00 am-4:40 pm
2 stops8h 40m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$162
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Fri 2/5
6:15 am-12:10 pm
Nonstop3h 55m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$165
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Sat 11/14
5:30 am-5:25 pm
2 stops9h 55m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$165
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Tue 12/8
6:30 am-12:25 pm
Nonstop3h 55m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$165
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Wed 11/18
9:25 am-7:35 pm
1 stop8h 10m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$175
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Sat 11/28
7:27 am-1:37 pm
Nonstop4h 10m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$189
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Sat 1/9
7:05 am-1:10 pm
Nonstop4h 05m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$189
Quickest round-trip
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Fri 11/20
12:15 am-6:05 am
Nonstop3h 50m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$189
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Fri 11/20
1:09 pm-11:49 pm
1 stop8h 40m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$200
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Seattle to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from Seattle with our price prediction graph.
SEA-ORD
SEA-MDW
SEA-PIA
SEA-MLI
SEA-BMI
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 Seattle to Illinois
SEA-USIL
SEA-ORD
SEA-MDW
SEA-PIA
SEA-MLI
What is the cheapest month to book a flight from Seattle to Illinois?
Currently, February is the cheapest month in which you can book a flight from Seattle to Illinois (average of $257). Flying from Seattle to Illinois in June is currently the most expensive (average of $420). 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 SEA to IL?
Find hourly flight availability from Seattle 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 October 25, 2026.
It’s typically best to fly out from Seattle to Illinois in the afternoon. Doing so could potentially save you 19% on the flight price compared to flying at noon, which is usually more expensive.
Weekly flight availability from Seattle to Illinois
Explore weekly flight availability from Seattle 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 October 25, 2026.
The most flights from SEA to USIL are scheduled on a Friday (55 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (20 on average).
How much does it cost to fly round-trip from Seattle to Illinois?
Airfare is below average for this route at the moment.
Seattle to Illinois flights typically cost between $312 and $488 in November.The cheapest round-trip price found within the last 5 days was $280 on Frontier (Nov 18-Dec 1).
How far ahead should I book a flight from Seattle to Illinois?
The price you pay for your flight from Seattle to Illinois may vary depending on when you book. For the best chance of a lower fare, look to book 60 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
What is the cheapest day to fly from Seattle to Illinois?
Use this chart to determine the cheapest time to fly round-trip from Seattle to Illinois. Price data was last updated on October 24, 2026.
Travelers seeking maximum savings on their Seattle to Illinois flight should consider departing on Tuesday at noon 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 October 25, 2026.
Read through reviews of airlines operating flights from Seattle to Illinois, such as Alaska Airlines,Southwest, andDelta. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Food
7.0
Comfort
7.8
Boarding
8.1
Overall
7.9
Crew
8.5
Entertainment
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Comfort
7.8
Boarding
8.1
Overall
7.9
Crew
8.5
Entertainment
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Comfort
7.8
Boarding
8.1
Overall
7.9
Crew
8.5
Entertainment
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Comfort
7.8
Boarding
8.1
Overall
7.9
Crew
8.5
Entertainment
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Comfort
7.8
Boarding
8.1
Overall
7.9
Crew
8.5
Entertainment
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Comfort
7.8
Boarding
8.1
Overall
7.9
Crew
8.5
Entertainment
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Related info for your journey
Find useful and relevant information for your journey from Seattle 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 Seattle 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.
Search flights from Seattle to Illinois by cabin class
Find flights from Seattle to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Seattle and Illinois flights
Browse other Seattle and Illinois flight options. Last updated on October 25, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Seattle to Illinois flights
Consider these flights traveling from Seattle to Illinois.
Top 6 airlines flying from Seattle to Illinois
Discover the top 6 airlines that operate flights from Seattle 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 7,457,451 searches. Data last updated October 25, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$171 | Average$356 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$177 | Average$380 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$189 | Average$456 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$195 | Average$485 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$208 | Average$315 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$276 | Average$444 | FlexibilityNo cancel fee | On-time63% |