$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 1/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ORD
Nov 8 — Nov 151
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 9, 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 9, 2026.
This Delta deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/287:15 am -
Nonstop4h 15m
Mon 11/25:30 pm -
Nonstop4h 46m
Deal found 10/8![Delta logo]()
$279
This Delta deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/295:30 pm -
Nonstop4h 04m
Fri 10/307:14 pm -
1 stop16h 05m
Deal found 10/8![Delta logo]()
$280
This Delta deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/2910:39 am -
Nonstop4h 14m
Tue 11/34:00 pm -
Nonstop4h 44m
Deal found 10/5![Delta logo]()
$281
This Delta deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/265:30 pm -
Nonstop4h 04m
Fri 10/307:14 pm -
1 stop16h 05m
Deal found 10/8![Delta logo]()
$282
This Southwest deal was found by Cheapflights users on 10/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/612:15 am -
Nonstop3h 50m
Sat 11/142:05 pm -
Nonstop4h 45m
Deal found 10/4![Southwest logo]()
$282
This Mytrip deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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.
Fri 10/304:27 pm -
2 stops26h 43m
Mon 11/26:30 am -
2 stops14h 03m
Deal found 10/8![Frontier logo]()
$284
This Southwest deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/112:15 am -
Nonstop3h 50m
Mon 11/910:00 pm -
Nonstop4h 45m
Deal found 10/5![Southwest logo]()
$284
This Super.com deal was found by Cheapflights users on 10/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/59:13 pm -
1 stop30h 00m
Sun 11/85:15 pm -
1 stop18h 30m
Deal found 10/9![Frontier logo]()
$285
This Kiwi.com deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/308:09 pm -
2 stops14h 42m
Wed 11/46:30 am -
1 stop10h 42m
Deal found 10/8![Frontier logo]()
$286
This Mytrip deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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.
Fri 11/137:48 pm -
2 stops19h 59m
Wed 11/1812:27 pm -
2 stops23h 18m
Deal found 10/8![Frontier logo]()
$286
This United Airlines deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/292:30 pm -
Nonstop4h 10m
Sat 10/3112:42 pm -
1 stop8h 04m
Deal found 10/8![United Airlines logo]()
$287
This Southwest deal was found by Cheapflights users on 10/9. Clicking the “Pick Dates” 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 11/65:30 am -
Nonstop3h 50m
Fri 11/135:40 pm -
1 stop7h 25m
Deal found 10/9![Southwest logo]()
$287
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 9, 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 9, 2026.
This Southwest deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/26:30 am -
Nonstop3h 55m
Wed 12/28:45 pm -
Nonstop4h 50m
Deal found 10/5![Southwest logo]()
$282
This Delta deal was found by Cheapflights users on 10/6. Clicking the “Pick Dates” 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 12/210:39 am -
Nonstop4h 11m
Mon 12/146:20 am -
1 stop6h 25m
Deal found 10/6![Delta logo]()
$287
This United Airlines deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/292:30 pm -
Nonstop4h 10m
Sat 10/3112:42 pm -
1 stop8h 04m
Deal found 10/8![United Airlines logo]()
$287
This American Airlines deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/3012:04 pm -
1 stop9h 13m
Tue 11/37:00 am -
1 stop8h 15m
Deal found 10/8![American Airlines logo]()
$379
This Southwest deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/196:30 am -
Nonstop3h 55m
Thu 11/2610:15 am -
Nonstop4h 45m
Deal found 10/5![Southwest logo]()
$282
This Delta deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 10/295:30 pm -
Nonstop4h 04m
Wed 11/48:05 am -
1 stop10h 11m
Deal found 10/7![Delta logo]()
$287
This United Airlines deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 12/102:05 pm -
Nonstop4h 10m
Tue 12/152:35 pm -
1 stop8h 46m
Deal found 10/8![United Airlines logo]()
$287
This Delta deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 10/285:30 pm -
Nonstop4h 04m
Tue 11/31:55 pm -
1 stop10h 10m
Deal found 10/7![Delta logo]()
$287
This Southwest deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 11/182:05 pm -
1 stop8h 10m
Mon 11/239:45 pm -
Nonstop4h 50m
Deal found 10/8![Southwest logo]()
$287
This United Airlines deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 12/114:04 pm -
1 stop5h 55m
Tue 12/154:20 pm -
1 stop7h 01m
Deal found 10/8![United Airlines logo]()
$297
This Delta deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 11/196:00 am -
1 stop8h 41m
Fri 11/206:40 am -
Nonstop4h 50m
Deal found 10/7![Delta logo]()
$287
This Southwest deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/316:50 am -
2 stops9h 50m
Sat 11/72:05 pm -
Nonstop4h 45m
Deal found 10/5![Southwest logo]()
$300
This American Airlines deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 11/63:10 pm -
1 stop6h 53m
Mon 11/95:37 pm -
1 stop8h 58m
Deal found 10/8![American Airlines logo]()
$379
This Delta deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 11/245:55 pm -
Nonstop4h 04m
Wed 11/252:44 pm -
1 stop9h 14m
Deal found 10/7![Delta logo]()
$287
This Southwest deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 11/65:30 am -
Nonstop3h 50m
Mon 11/95:20 pm -
2 stops7h 45m
Deal found 10/8![Southwest logo]()
$312
This Delta deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 11/1911:15 pm -
1 stop6h 34m
Sun 11/227:30 am -
1 stop9h 25m
Deal found 10/7![Delta logo]()
$297
This United Airlines deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/302:30 pm -
1 stop6h 29m
Tue 11/38:13 am -
2 stops10h 14m
Deal found 10/8![United Airlines logo]()
$384
This Southwest deal was found by Cheapflights users on 10/6. Clicking the “Pick Dates” 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
Sat 12/122:05 pm -
Nonstop4h 40m
Deal found 10/6![Southwest logo]()
$323
This Delta deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 12/2411:59 pm -
1 stop7h 20m
Sat 1/26:00 am -
Nonstop4h 54m
Deal found 10/8![Delta logo]()
$307
This American Airlines deal was found by Cheapflights users on 10/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/2810:31 am -
1 stop7h 54m
Wed 11/47:11 am -
1 stop9h 40m
Deal found 10/4![American Airlines logo]()
$470
This United Airlines deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/57:00 am -
1 stop7h 45m
Wed 12/95:30 pm -
1 stop7h 13m
Deal found 10/5![United Airlines logo]()
$421
This Southwest deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 11/245:35 am -
2 stops8h 05m
Fri 11/276:05 pm -
1 stop8h 40m
Deal found 10/8![Southwest logo]()
$355
This American Airlines deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/1612:04 pm -
1 stop8h 54m
Mon 10/192:30 pm -
1 stop7h 45m
Deal found 10/5![American Airlines logo]()
$501
This United Airlines deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/22:05 pm -
1 stop7h 04m
Wed 12/98:40 am -
2 stops11h 48m
Deal found 10/5![United Airlines logo]()
$426
This American Airlines deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 11/43:10 pm -
1 stop7h 00m
Wed 11/116:05 am -
1 stop10h 15m
Deal found 10/7![American Airlines logo]()
$507
This Delta deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 10/2611:59 pm -
1 stop9h 55m
Wed 10/281:27 pm -
1 stop7h 08m
Deal found 10/7![Delta logo]()
$382
This United Airlines deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/82:05 pm -
1 stop7h 04m
Tue 12/158:40 am -
2 stops9h 42m
Deal found 10/5![United Airlines logo]()
$426
This Southwest deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 11/85:30 am -
Nonstop3h 50m
Mon 11/305:00 pm -
2 stops8h 10m
Deal found 10/8![Southwest logo]()
$388
This United Airlines deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/87:00 am -
1 stop7h 45m
Sat 12/1210:45 am -
2 stops13h 13m
Deal found 10/5![United Airlines logo]()
$426
This Southwest deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 12/268:15 pm -
1 stop7h 25m
Fri 1/110:00 am -
2 stops13h 30m
Deal found 10/7![Southwest logo]()
$394
Last-minute flights from Seattle to IllinoisDiscover last-minute flight deals from Seattle to Illinois. Data last updated October 9, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Illinois. Data last updated October 9, 2026 and is based on user searches.
This Delta deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/265:30 pm -
Nonstop4h 04m
Fri 10/307:14 pm -
1 stop16h 05m
Deal found 10/8![Delta logo]()
$282
This Delta deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/285:30 pm -
Nonstop4h 04m
Sat 10/316:35 am -
Nonstop4h 45m
Deal found 10/8![Delta logo]()
$279
This Delta deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/299:35 pm -
1 stop18h 15m
Mon 11/25:30 pm -
Nonstop4h 46m
Deal found 10/8![Delta logo]()
$280
This Delta deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/2910:39 am -
Nonstop4h 14m
Tue 11/34:00 pm -
Nonstop4h 44m
Deal found 10/5![Delta logo]()
$281
This United Airlines deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/292:30 pm -
Nonstop4h 10m
Sat 10/3112:42 pm -
1 stop8h 04m
Deal found 10/8![United Airlines logo]()
$287
This Mytrip deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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.
Fri 10/304:27 pm -
2 stops26h 43m
Mon 11/26:30 am -
2 stops14h 03m
Deal found 10/8![Frontier logo]()
$284
This Kiwi.com deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 10/308:09 pm -
2 stops14h 42m
Wed 11/46:30 am -
1 stop10h 42m
Deal found 10/8![Frontier logo]()
$286
This Southwest deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/112:15 am -
Nonstop3h 50m
Mon 11/910:00 pm -
Nonstop4h 45m
Deal found 10/5![Southwest logo]()
$284
This Super.com deal was found by Cheapflights users on 10/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/59:13 pm -
1 stop30h 00m
Sun 11/85:15 pm -
1 stop18h 30m
Deal found 10/9![Frontier logo]()
$285
This Southwest deal was found by Cheapflights users on 10/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/612:15 am -
Nonstop3h 50m
Sat 11/142:05 pm -
Nonstop4h 45m
Deal found 10/4![Southwest logo]()
$282
This Southwest deal was found by Cheapflights users on 10/9. Clicking the “Pick Dates” 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 11/65:30 am -
Nonstop3h 50m
Fri 11/135:40 pm -
1 stop7h 25m
Deal found 10/9![Southwest logo]()
$287
This Mytrip deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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.
Fri 11/137:48 pm -
2 stops19h 59m
Wed 11/1812:27 pm -
2 stops23h 18m
Deal found 10/8![Frontier logo]()
$286
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 9, 2026.
Search for one-way flight options from Seattle to Illinois. Find affordable one-way fares based on user searches. Data last updated October 9, 2026.
This Alaska Airlines deal was found by Cheapflights users on 10/9. Clicking the “Pick Dates” 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 1/811:45 am -
Nonstop4h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/9![Alaska Airlines logo]()
$159
This Southwest deal was found by Cheapflights users on 10/9. Clicking the “Pick Dates” 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 11/95:30 am -
Nonstop3h 50m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/9![Southwest logo]()
$159
This Super.com deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.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
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$160
This Kiwi.com deal was found by Cheapflights users on 10/7. Clicking the “Pick Dates” 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 1/45:25 pm -
2 stops40h 48m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Frontier logo]()
$160
This Kiwi.com deal was found by Cheapflights users on 10/8. Clicking the “Pick Dates” 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 11/234:37 pm -
2 stops25h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/8![Frontier logo]()
$161
This Super.com deal was found by Cheapflights users on 10/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/214:37 pm -
1 stop6h 16m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/4![Frontier logo]()
$162
This Cheapflightsfares deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/44:58 pm -
1 stop5h 55m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$163
This Frontier deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/24:58 pm -
1 stop5h 55m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$165
This Kiwi.com deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/24:58 pm -
2 stops25h 50m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$165
This Mytrip deal was found by Cheapflights users on 10/6. Clicking the “Pick Dates” 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 11/2510:18 am -
1 stop17h 56m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/6![Frontier logo]()
$166
This Kiwi.com deal was found by Cheapflights users on 10/6. Clicking the “Pick Dates” 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 11/59:13 pm -
2 stops36h 12m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/6![Frontier logo]()
$166
This Cheapflightsfares deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/314:27 pm -
1 stop5h 54m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$167
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 9, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $279 (Delta) |
One-way from | $159 (Alaska Airlines) |
Popular in | June |
Cheapest in | February |
Average price | $378 |
Good round-trip deal | $364 or less |
Good one-way deal | $205 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 9, 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 - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Mon 11/9
2:30 pm-8:40 pm
Nonstop4h 10m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$159
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Fri 11/20
10:39 am-4:47 pm
Nonstop4h 08m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$169
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Sun 12/20
5:52 pm-11:59 pm
Nonstop4h 07m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$169
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Tue 1/5
8:45 am-10:08 pm
2 stops11h 23m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$170
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Sat 1/9
2:30 pm-8:43 am
2 stops16h 13m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$173
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Tue 11/10
12:31 pm-8:50 am
2 stops18h 19m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$173
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Fri 1/8
12:00 pm-8:43 am
2 stops18h 43m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$188
SeattleChicago
SEA Seattle/Tacoma Intl - MDW Chicago Midway
SEAMDW
Seattle/Tacoma Intl
Sun 11/1
5:15 am-5:35 pm
2 stops10h 20m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$204
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Sun 1/3
9:25 pm-9:24 am
1 stop9h 59m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$205
SeattleChicago
SEA Seattle/Tacoma Intl - ORD Chicago O'Hare Intl
SEAORD
Seattle/Tacoma Intl
Thu 12/3
5:51 pm-11:59 pm
Nonstop4h 08m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$209
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-BMI
SEA-PIA
SEA-MLI
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-BMI
SEA-PIA
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 $262). 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 9, 2026.
It’s typically best to fly out from Seattle to Illinois in the evening. Doing so could potentially save you 5% 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 9, 2026.
The most flights from SEA to USIL are scheduled on a Wednesday (52 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (27 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 $303 and $466 in October.The cheapest round-trip price found within the last 5 days was $279 on Delta (Oct 28-Oct 29).
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 30 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 3, 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 9, 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.
Boarding
8.1
Entertainment
7.0
Crew
8.5
Comfort
7.8
Food
7.0
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Entertainment
7.0
Crew
8.5
Comfort
7.8
Food
7.0
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Entertainment
7.0
Crew
8.5
Comfort
7.8
Food
7.0
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Entertainment
7.0
Crew
8.5
Comfort
7.8
Food
7.0
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Entertainment
7.0
Crew
8.5
Comfort
7.8
Food
7.0
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Entertainment
7.0
Crew
8.5
Comfort
7.8
Food
7.0
Overall
7.9
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 9, 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 9, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$168 | Average$373 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$177 | Average$379 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$180 | Average$453 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$183 | Average$313 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$194 | Average$479 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$276 | Average$432 | FlexibilityNo cancel fee | On-time63% |