$96+ Cheap flights from Portland (PDX) 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 9/5. Fares are subject to change and may not be available on all flights or dates of travel.
PDX — ORD
Aug 6 — Aug 131
Round-trip
1 adult, Economy
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Cheapest flights from Portland to IllinoisExplore the most affordable flight options available from Portland to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 7, 2026.
Explore the most affordable flight options available from Portland to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 7, 2026.
This Southwest deal was found by Cheapflights users on 7/7. 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 8/229:00 am
PDX
- STL
1 stop7h 25m
Southwest
Sat 8/298:30 am
STL
- PDX
Nonstop4h 10m
Southwest
Deal found 7/7![Southwest logo]()
$201
This Delta deal was found by Cheapflights users on 7/7. 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 8/1012:35 am
PDX
- STL
1 stop7h 48m
Delta
Tue 8/187:45 pm
STL
- PDX
1 stop5h 54m
Delta
Deal found 7/7![Delta logo]()
$211
This Southwest deal was found by Cheapflights users on 7/7. 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.
Mon 8/3110:45 pm
PDX
- STL
1 stop9h 20m
Southwest
Wed 9/211:55 am
STL
- PDX
1 stop8h 20m
Southwest
Deal found 7/7![Southwest logo]()
$212
This Southwest deal was found by Cheapflights users on 7/7. 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.
Wed 8/196:25 pm
PDX
- STL
1 stop13h 25m
Southwest
Mon 8/246:25 pm
STL
- PDX
1 stop6h 40m
Southwest
Deal found 7/7![Southwest logo]()
$235
This Delta deal was found by Cheapflights users on 7/7. 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.
Fri 11/65:15 pm
PDX
- STL
1 stop5h 19m
Delta
Wed 11/116:30 am
STL
- PDX
1 stop7h 59m
Delta
Deal found 7/7![Delta logo]()
$238
This Frontier deal was found by Cheapflights users on 7/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/19:34 pm
PDX
- STL
1 stop12h 17m
Frontier
Mon 10/512:46 pm
STL
- PDX
1 stop9h 53m
Frontier
Deal found 7/3![Frontier logo]()
$240
This United Airlines deal was found by Cheapflights users on 7/7. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/48:35 am
PDX
- STL
1 stop7h 42m
United Airlines
Wed 8/57:23 pm
STL
- PDX
1 stop7h 27m
United Airlines
Deal found 7/7![United Airlines logo]()
$245
This Mytrip deal was found by Cheapflights users on 7/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/59:34 pm
PDX
- STL
1 stop12h 17m
Frontier
Thu 10/85:19 pm
STL
- PDX
1 stop29h 20m
Frontier
Deal found 7/3![Frontier logo]()
$249
This CheapOair deal was found by Cheapflights users on 7/7. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/119:34 pm
PDX
- STL
1 stop12h 17m
Frontier
Sun 9/138:10 pm
STL
- PDX
1 stop22h 25m
Frontier
Deal found 7/7![Frontier logo]()
$250
This Southwest deal was found by Cheapflights users on 7/7. 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 8/229:00 am
PDX
- STL
1 stop9h 20m
Southwest
Sun 8/239:55 pm
STL
- PDX
Nonstop4h 10m
Southwest
Deal found 7/7![Southwest logo]()
$255
This CheapOair deal was found by Cheapflights users on 7/7. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/55:21 pm
PDX
- ORD
1 stop25h 31m
Frontier
Sun 8/239:20 pm
ORD
- PDX
1 stop16h 15m
Frontier
Deal found 7/7![Frontier logo]()
$327
This Southwest deal was found by Cheapflights users on 7/7. 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.
Tue 8/411:30 pm
PDX
- MDW
Nonstop3h 55m
Southwest
Tue 8/116:00 am
MDW
- PDX
1 stop7h 20m
Southwest
Deal found 7/7![Southwest logo]()
$327
Best flights from Portland to IllinoisDiscover carefully curated flight deals from Portland to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 7, 2026.
Discover carefully curated flight deals from Portland to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 7, 2026.
This Southwest deal was found by Cheapflights users on 7/7. 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.
Wed 8/196:25 pm
PDX
- STL
1 stop13h 25m
Southwest
Mon 8/246:25 pm
STL
- PDX
1 stop6h 40m
Southwest
Deal found 7/7![Southwest logo]()
$235
This Delta deal was found by Cheapflights users on 7/6. 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.
Thu 9/312:35 am
PDX
- STL
1 stop7h 48m
Delta
Wed 9/95:00 pm
STL
- PDX
1 stop7h 31m
Delta
Deal found 7/6![Delta logo]()
$318
This United Airlines deal was found by Cheapflights users on 7/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/110:50 am
PDX
- STL
2 stops9h 10m
United Airlines
Wed 11/44:40 pm
STL
- PDX
1 stop6h 28m
United Airlines
Deal found 7/3![United Airlines logo]()
$322
This American Airlines deal was found by Cheapflights users on 7/7. 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.
Tue 9/157:00 am
PDX
- PIA
1 stop6h 57m
American Airlines
Sun 9/205:28 pm
PIA
- PDX
1 stop8h 39m
American Airlines
Deal found 7/7![American Airlines logo]()
$340
This Alaska Airlines deal was found by Cheapflights users on 7/5. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/1210:49 am
PDX
- STL
Nonstop3h 48m
Alaska Airlines
Wed 8/125:37 pm
STL
- PDX
Nonstop4h 10m
Alaska Airlines
Deal found 7/5![Alaska Airlines logo]()
$372
This Southwest deal was found by Cheapflights users on 7/7. 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 8/229:00 am
PDX
- STL
1 stop9h 20m
Southwest
Sun 8/239:55 pm
STL
- PDX
Nonstop4h 10m
Southwest
Deal found 7/7![Southwest logo]()
$255
This American Airlines deal was found by Cheapflights users on 7/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/3012:45 am
PDX
- MLI
1 stop7h 54m
American Airlines
Fri 8/76:45 pm
MLI
- PDX
1 stop7h 14m
American Airlines
Deal found 7/3![American Airlines logo]()
$349
This Delta deal was found by Cheapflights users on 7/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/2312:25 am
PDX
- MDW
1 stop6h 23m
Delta
Wed 9/302:00 pm
MDW
- PDX
1 stop8h 16m
Delta
Deal found 7/2![Delta logo]()
$369
This United Airlines deal was found by Cheapflights users on 7/5. 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 8/44:15 pm
PDX
- STL
1 stop5h 42m
United Airlines
Tue 8/115:10 am
STL
- PDX
2 stops8h 50m
United Airlines
Deal found 7/5![United Airlines logo]()
$370
This Southwest deal was found by Cheapflights users on 7/7. 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.
Thu 8/2012:40 pm
PDX
- MDW
2 stops9h 05m
Southwest
Sun 8/236:10 am
MDW
- PDX
1 stop7h 55m
Southwest
Deal found 7/7![Southwest logo]()
$338
This Alaska Airlines deal was found by Cheapflights users on 7/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/2310:59 pm
PDX
- ORD
Nonstop4h 01m
Alaska Airlines
Thu 8/67:20 am
ORD
- PDX
Nonstop4h 25m
Alaska Airlines
Deal found 7/2![Alaska Airlines logo]()
$383
This American Airlines deal was found by Cheapflights users on 7/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/225:07 am
PDX
- CMI
1 stop7h 09m
American Airlines
Wed 7/296:36 pm
CMI
- PDX
1 stop8h 14m
American Airlines
Deal found 7/3![American Airlines logo]()
$373
This United Airlines deal was found by Cheapflights users on 7/6. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/317:00 am
PDX
- ORD
Nonstop4h 13m
United Airlines
Wed 8/57:55 pm
ORD
- PDX
Nonstop4h 35m
United Airlines
Deal found 7/6![United Airlines logo]()
$383
This Alaska Airlines deal was found by Cheapflights users on 7/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/2410:59 pm
PDX
- ORD
Nonstop4h 01m
Alaska Airlines
Sun 8/27:20 am
ORD
- PDX
Nonstop4h 25m
Alaska Airlines
Deal found 7/2![Alaska Airlines logo]()
$383
This Southwest deal was found by Cheapflights users on 7/4. 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 8/710:45 pm
PDX
- STL
2 stops12h 40m
Southwest
Mon 8/106:15 pm
STL
- PDX
1 stop6h 50m
Southwest
Deal found 7/4![Southwest logo]()
$369
This Delta deal was found by Cheapflights users on 7/5. 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.
Sun 8/305:30 am
PDX
- ORD
1 stop5h 53m
Delta
Mon 9/77:00 am
ORD
- PDX
1 stop6h 45m
Delta
Deal found 7/5![Delta logo]()
$409
This Alaska Airlines deal was found by Cheapflights users on 7/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/2310:59 pm
PDX
- ORD
Nonstop4h 01m
Alaska Airlines
Sun 8/27:20 am
ORD
- PDX
Nonstop4h 25m
Alaska Airlines
Deal found 7/2![Alaska Airlines logo]()
$383
This United Airlines deal was found by Cheapflights users on 7/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/278:46 am
PDX
- MLI
1 stop6h 57m
United Airlines
Sat 10/316:30 am
MLI
- PDX
1 stop7h 23m
United Airlines
Deal found 7/2![United Airlines logo]()
$391
This Delta deal was found by Cheapflights users on 7/4. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/2511:10 pm
PDX
- MDW
1 stop7h 57m
Delta
Mon 9/287:13 pm
MDW
- PDX
1 stop5h 57m
Delta
Deal found 7/4![Delta logo]()
$409
This Southwest deal was found by Cheapflights users on 7/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/195:50 am
PDX
- MDW
2 stops8h 45m
Southwest
Sun 8/235:25 am
MDW
- PDX
1 stop7h 40m
Southwest
Deal found 7/3![Southwest logo]()
$380
This Alaska Airlines deal was found by Cheapflights users on 7/6. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/410:59 pm
PDX
- ORD
Nonstop4h 01m
Alaska Airlines
Sat 8/87:20 am
ORD
- PDX
Nonstop4h 25m
Alaska Airlines
Deal found 7/6![Alaska Airlines logo]()
$383
This American Airlines deal was found by Cheapflights users on 7/4. 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 7/155:07 am
PDX
- CMI
1 stop7h 09m
American Airlines
Wed 7/226:36 pm
CMI
- PDX
1 stop8h 14m
American Airlines
Deal found 7/4![American Airlines logo]()
$444
This United Airlines deal was found by Cheapflights users on 7/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/1711:40 pm
PDX
- MLI
1 stop7h 00m
United Airlines
Tue 7/211:14 pm
MLI
- PDX
1 stop7h 33m
United Airlines
Deal found 7/2![United Airlines logo]()
$405
This Southwest deal was found by Cheapflights users on 7/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/710:45 pm
PDX
- MDW
1 stop8h 15m
Southwest
Sun 9/139:20 pm
MDW
- PDX
Nonstop4h 10m
Southwest
Deal found 7/3![Southwest logo]()
$384
This Delta deal was found by Cheapflights users on 7/5. 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.
Tue 10/205:49 pm
PDX
- EVV
2 stops13h 35m
Delta
Tue 10/271:50 pm
EVV
- PDX
1 stop9h 50m
Delta
Deal found 7/5![Delta logo]()
$424
This Alaska Airlines deal was found by Cheapflights users on 7/5. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/710:59 pm
PDX
- ORD
Nonstop4h 01m
Alaska Airlines
Sun 8/97:20 am
ORD
- PDX
Nonstop4h 25m
Alaska Airlines
Deal found 7/5![Alaska Airlines logo]()
$389
This United Airlines deal was found by Cheapflights users on 7/6. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/1810:40 pm
PDX
- ORD
Nonstop4h 05m
United Airlines
Wed 7/224:15 pm
ORD
- PDX
Nonstop4h 32m
United Airlines
Deal found 7/6![United Airlines logo]()
$407
This American Airlines deal was found by Cheapflights users on 7/4. 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 7/295:49 am
PDX
- EVV
1 stop8h 21m
American Airlines
Wed 8/512:20 pm
EVV
- PDX
1 stop8h 39m
American Airlines
Deal found 7/4![American Airlines logo]()
$466
This Southwest deal was found by Cheapflights users on 7/5. 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.
Fri 9/1112:40 pm
PDX
- MDW
2 stops9h 05m
Southwest
Mon 9/149:00 am
MDW
- PDX
1 stop8h 00m
Southwest
Deal found 7/5![Southwest logo]()
$390
This Alaska Airlines deal was found by Cheapflights users on 7/5. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2910:32 am
PDX
- STL
1 stop8h 20m
Alaska Airlines
Wed 9/3010:14 am
STL
- PDX
1 stop8h 19m
Alaska Airlines
Deal found 7/5![Alaska Airlines logo]()
$397
Last-minute flights from Portland to IllinoisDiscover last-minute flight deals from Portland to Illinois. Data last updated July 7, 2026 and is based on user searches.
Discover last-minute flight deals from Portland to Illinois. Data last updated July 7, 2026 and is based on user searches.
This eDestinos deal was found by Cheapflights users on 7/6. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/145:16 pm
PDX
- ORD
1 stop25h 36m
Frontier
Fri 7/179:13 pm
ORD
- PDX
1 stop16h 22m
Frontier
Deal found 7/6![Frontier logo]()
$329
This CheapOair deal was found by Cheapflights users on 7/4. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/225:21 pm
PDX
- STL
1 stop24h 02m
Frontier
Wed 7/297:03 pm
STL
- PDX
1 stop25h 01m
Frontier
Deal found 7/4![Frontier logo]()
$259
This United Airlines deal was found by Cheapflights users on 7/7. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/48:35 am
PDX
- STL
1 stop7h 42m
United Airlines
Wed 8/57:23 pm
STL
- PDX
1 stop7h 27m
United Airlines
Deal found 7/7![United Airlines logo]()
$245
This Southwest deal was found by Cheapflights users on 7/7. 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.
Tue 8/411:30 pm
PDX
- MDW
Nonstop3h 55m
Southwest
Tue 8/116:00 am
MDW
- PDX
1 stop7h 20m
Southwest
Deal found 7/7![Southwest logo]()
$327
This Southwest deal was found by Cheapflights users on 7/7. 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.
Thu 8/612:40 pm
PDX
- MDW
2 stops9h 05m
Southwest
Wed 8/125:20 pm
MDW
- PDX
1 stop7h 00m
Southwest
Deal found 7/7![Southwest logo]()
$329
This Delta deal was found by Cheapflights users on 7/7. 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 8/1012:35 am
PDX
- STL
1 stop7h 48m
Delta
Tue 8/187:45 pm
STL
- PDX
1 stop5h 54m
Delta
Deal found 7/7![Delta logo]()
$211
This Southwest deal was found by Cheapflights users on 7/7. 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.
Wed 8/196:25 pm
PDX
- STL
1 stop13h 25m
Southwest
Mon 8/246:25 pm
STL
- PDX
1 stop6h 40m
Southwest
Deal found 7/7![Southwest logo]()
$235
This CheapOair deal was found by Cheapflights users on 7/7. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/201:47 pm
PDX
- STL
1 stop26h 03m
Frontier
Sun 8/236:45 pm
STL
- PDX
1 stop24h 36m
Frontier
Deal found 7/7![Frontier logo]()
$250
This Southwest deal was found by Cheapflights users on 7/7. 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.
Thu 8/2012:40 pm
PDX
- MDW
2 stops9h 05m
Southwest
Sun 8/239:20 pm
MDW
- PDX
Nonstop4h 10m
Southwest
Deal found 7/7![Southwest logo]()
$328
This Southwest deal was found by Cheapflights users on 7/7. 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 8/229:00 am
PDX
- STL
1 stop7h 25m
Southwest
Sat 8/298:30 am
STL
- PDX
Nonstop4h 10m
Southwest
Deal found 7/7![Southwest logo]()
$201
This Southwest deal was found by Cheapflights users on 7/7. 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 8/229:00 am
PDX
- STL
1 stop9h 20m
Southwest
Sun 8/239:55 pm
STL
- PDX
Nonstop4h 10m
Southwest
Deal found 7/7![Southwest logo]()
$255
This Southwest deal was found by Cheapflights users on 7/7. 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.
Mon 8/3110:45 pm
PDX
- STL
1 stop9h 20m
Southwest
Wed 9/211:55 am
STL
- PDX
1 stop8h 20m
Southwest
Deal found 7/7![Southwest logo]()
$212
One-way flights from Portland to IllinoisSearch for one-way flight options from Portland to Illinois. Find affordable one-way fares based on user searches. Data last updated July 7, 2026.
Search for one-way flight options from Portland to Illinois. Find affordable one-way fares based on user searches. Data last updated July 7, 2026.
This Southwest deal was found by Cheapflights users on 7/7. 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 9/59:45 am
PDX
- STL
Nonstop3h 45m
Southwest
Deal found 7/7![Southwest logo]()
$96
This Southwest deal was found by Cheapflights users on 7/7. 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 8/229:00 am
PDX
- STL
1 stop9h 20m
Southwest
Deal found 7/7![Southwest logo]()
$106
This Southwest deal was found by Cheapflights users on 7/7. 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.
Mon 9/711:30 pm
PDX
- STL
1 stop8h 05m
Southwest
Deal found 7/7![Southwest logo]()
$123
This Frontier deal was found by Cheapflights users on 7/7. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/29:34 pm
PDX
- STL
1 stop12h 17m
Frontier
Deal found 7/7![Frontier logo]()
$126
This Trip.com deal was found by Cheapflights users on 7/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/145:49 pm
PDX
- STL
1 stop22h 26m
Frontier
Deal found 7/3![Frontier logo]()
$129
This Mytrip deal was found by Cheapflights users on 7/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/163:22 pm
PDX
- STL
1 stop25h 53m
Frontier
Deal found 7/4![Frontier logo]()
$130
This CheapOair deal was found by Cheapflights users on 7/7. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/315:49 pm
PDX
- STL
1 stop22h 26m
Frontier
Deal found 7/7![Frontier logo]()
$131
This United Airlines deal was found by Cheapflights users on 7/7. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/237:02 am
PDX
- STL
1 stop6h 41m
United Airlines
Deal found 7/7![United Airlines logo]()
$132
This Kiwi.com deal was found by Cheapflights users on 7/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/55:21 pm
PDX
- STL
1 stop24h 02m
Frontier
Deal found 7/4![Frontier logo]()
$134
This Trip.com deal was found by Cheapflights users on 7/7. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/225:21 pm
PDX
- STL
1 stop24h 02m
Frontier
Deal found 7/7![Frontier logo]()
$138
This Kiwi.com deal was found by Cheapflights users on 7/5. 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.
Thu 9/173:22 pm
PDX
- ORD
1 stop28h 13m
Frontier
Deal found 7/5![Frontier logo]()
$166
This Kiwi.com deal was found by Cheapflights users on 7/7. 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.
Tue 10/63:22 pm
PDX
- ORD
1 stop16h 39m
Frontier
Deal found 7/7![Frontier logo]()
$167
Find flight deals from Portland to Illinois
Keep the following information in mind while searching for Portland to Illinois flight deals. Data was last updated July 7, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $201 (Southwest) |
One-way from | $96 (Southwest) |
Popular in | November |
Cheapest in | January |
Average price | $363 |
Good round-trip deal | $394 or less |
Good one-way deal | $224 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Portland 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 7, 2026.
Use the filters below to find and compare flights from Portland to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
PortlandSt. Louis
PDX - STL
PDXSTL
Portland
Wed 8/19
6:25 pm-9:50 am
1 stop13h 25m
Lambert-St Louis
Mon 8/24
6:25 pm-11:05 pm
1 stop6h 40m
$235
PortlandSt. Louis
PDX - STL
PDXSTL
Portland
Sat 8/22
9:00 am-8:20 pm
1 stop9h 20m
Lambert-St Louis
Sun 8/23
9:55 pm-12:05 am
Nonstop4h 10m
$255
PortlandSt. Louis
PDX - STL
PDXSTL
Portland
Thu 9/3
12:35 am-10:23 am
1 stop7h 48m
Lambert-St Louis
Wed 9/9
5:00 pm-10:31 pm
1 stop7h 31m
$318
PortlandSt. Louis
PDX - STL
PDXSTL
Portland
Tue 9/1
10:50 am-10:00 pm
2 stops9h 10m
Lambert-St Louis
Wed 11/4
4:40 pm-9:08 pm
1 stop6h 28m
$322
PortlandChicago
PDX - MDW
PDXMDW
Portland
Thu 8/20
12:40 pm-11:45 pm
2 stops9h 05m
Chicago Midway
Sun 8/23
6:10 am-12:05 pm
1 stop7h 55m
$338
PortlandPeoria
PDX - PIA
PDXPIA
Portland
Tue 9/15
7:00 am-3:57 pm
1 stop6h 57m
Greater Peoria
Sun 9/20
5:28 pm-12:07 am
1 stop8h 39m
$340
PortlandMoline
PDX - MLI
PDXMLI
Portland
Thu 7/30
12:45 am-10:39 am
1 stop7h 54m
Moline Quad-City
Fri 8/7
6:45 pm-11:59 pm
1 stop7h 14m
$349
PortlandChicago
PDX - MDW
PDXMDW
Portland
Wed 9/23
12:25 am-8:48 am
1 stop6h 23m
Chicago Midway
Wed 9/30
2:00 pm-8:16 pm
1 stop8h 16m
$369
PortlandSt. Louis
PDX - STL
PDXSTL
Portland
Fri 8/7
10:45 pm-1:25 pm
2 stops12h 40m
Lambert-St Louis
Mon 8/10
6:15 pm-11:05 pm
1 stop6h 50m
$369
PortlandSt. Louis
PDX - STL
PDXSTL
Portland
Tue 8/4
4:15 pm-11:57 pm
1 stop5h 42m
Lambert-St Louis
Tue 8/11
5:10 am-12:00 pm
2 stops8h 50m
$370
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Portland to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from Portland with our price prediction graph.
PDX-STL
PDX-PIA
PDX-MLI
PDX-MDW
PDX-ORD
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 Portland to Illinois
PDX-USIL
PDX-STL
PDX-PIA
PDX-MLI
PDX-MDW
What is the cheapest month to book a flight from Portland to Illinois?
Currently, November is the cheapest month in which you can book a flight from Portland to Illinois (average of $103). Flying from Portland to Illinois in October is currently the most expensive (average of $743). 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 PDX to IL?
Find hourly flight availability from Portland 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 7, 2026.
It’s typically best to fly out from Portland to Illinois in the afternoon. Doing so could potentially save you 13% on the flight price compared to flying in the morning, which is usually more expensive.
Weekly flight availability from Portland to Illinois
Explore weekly flight availability from Portland 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 7, 2026.
The most flights from PDX to USIL are scheduled on a Monday (35 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 Portland to Illinois?
How far ahead should I book a flight from Portland to Illinois?
To ensure you get the cheapest price possible for a flight from Portland to Illinois, you should look to book at least 57 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 Portland to Illinois?
Use this chart to determine the cheapest time to fly round-trip from Portland to Illinois. Price data was last updated on July 4, 2026.
Travelers seeking maximum savings on their Portland to Illinois flight should consider departing on Friday at noon when fares are most often at their lowest. Sunday afternoons 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 7, 2026.
Read reviews from past customers who have flown Alaska Airlines,Southwest, andDelta from Portland to Illinois. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Overall
7.9
Food
7.0
Crew
8.5
Comfort
7.8
Entertainment
7.0
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Nov 2025
PDX - BNA
Overall
7.9
Food
7.0
Crew
8.5
Comfort
7.8
Entertainment
7.0
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Nov 2025
PDX - BNA
Overall
7.9
Food
7.0
Crew
8.5
Comfort
7.8
Entertainment
7.0
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Nov 2025
PDX - BNA
Overall
7.9
Food
7.0
Crew
8.5
Comfort
7.8
Entertainment
7.0
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Nov 2025
PDX - BNA
Overall
7.9
Food
7.0
Crew
8.5
Comfort
7.8
Entertainment
7.0
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Nov 2025
PDX - BNA
Overall
7.9
Food
7.0
Crew
8.5
Comfort
7.8
Entertainment
7.0
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Nov 2025
PDX - BNA
Related info for your journey
Find useful and relevant information for your journey from Portland 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 Portland to Illinois
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Illinois by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Portland to Illinois by cabin class
Find flights from Portland to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Portland and Illinois flights
Browse other Portland and Illinois flight options. Last updated on July 7, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Portland to Illinois flights
Consider these flights traveling from Portland to Illinois.
Top 7 airlines flying from Portland to Illinois
Discover the top 7 airlines that operate flights from Portland 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 7, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$93 | Average$217 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$96 | Average$238 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$125 | Average$256 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$170 | Average$459 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$207 | Average$373 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$222 | Average$454 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$231 | Average$360 | FlexibilityNo cancel fee | On-time63% |