$140+ Cheap flights from Montana 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 9/27. Fares are subject to change and may not be available on all flights or dates of travel.
BZN — ORD
Sep 3 — Sep 101
Round-trip
1 adult, Economy
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Cheapest flights from Montana to IllinoisExplore the most affordable flight options available from Montana to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 4, 2026.
Explore the most affordable flight options available from Montana to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 4, 2026.
This United Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 9/511:43 am
BIL
- ORD
Nonstop3h 05m
United Airlines
Sat 9/128:40 am
ORD
- BIL
Nonstop3h 22m
United Airlines
Deal found 7/31![United Airlines logo]()
$261
This Delta deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/512:57 pm
BIL
- ORD
2 stops10h 00m
Delta
Sat 9/123:29 pm
ORD
- BIL
1 stop5h 38m
Delta
Deal found 7/31![Delta logo]()
$286
This American Airlines deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” 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 10/21:40 pm
BZN
- ORD
Nonstop3h 19m
American Airlines
Sun 10/410:16 am
ORD
- BZN
Nonstop3h 27m
American Airlines
Deal found 7/30![American Airlines logo]()
$295
This American Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 9/312:55 pm
BZN
- ORD
Nonstop3h 21m
American Airlines
Sun 9/69:45 am
ORD
- BZN
Nonstop3h 20m
American Airlines
Deal found 8/1![American Airlines logo]()
$296
This United Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 9/22:30 pm
BZN
- ORD
1 stop7h 16m
United Airlines
Sat 9/54:15 pm
ORD
- BZN
Nonstop3h 27m
United Airlines
Deal found 7/31![United Airlines logo]()
$301
This United Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 11/145:00 am
BIL
- ORD
1 stop5h 19m
United Airlines
Sat 11/217:00 am
ORD
- BIL
1 stop7h 29m
United Airlines
Deal found 7/31![United Airlines logo]()
$302
This Southwest deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/241:35 pm
BZN
- MDW
1 stop7h 30m
Southwest
Mon 9/2810:50 am
MDW
- BZN
Nonstop3h 05m
Southwest
Deal found 8/1![Southwest logo]()
$305
This American Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 9/1612:28 pm
BIL
- ORD
Nonstop3h 02m
American Airlines
Wed 9/239:41 am
ORD
- BIL
Nonstop3h 16m
American Airlines
Deal found 8/1![American Airlines logo]()
$309
This United Airlines deal was found by Cheapflights users on 8/3. 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.
Fri 9/42:30 pm
BZN
- ORD
1 stop7h 16m
United Airlines
Sun 9/64:26 pm
ORD
- BZN
1 stop5h 53m
United Airlines
Deal found 8/3![United Airlines logo]()
$310
This United Airlines deal was found by Cheapflights users on 8/3. 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.
Fri 10/305:55 pm
BIL
- ORD
1 stop5h 04m
United Airlines
Wed 11/43:56 pm
ORD
- BIL
1 stop6h 18m
United Airlines
Deal found 8/3![United Airlines logo]()
$312
This Southwest deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/224:15 pm
BZN
- MDW
1 stop5h 00m
Southwest
Mon 10/266:05 am
MDW
- BZN
1 stop5h 20m
Southwest
Deal found 8/1![Southwest logo]()
$315
This Delta deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 10/23:38 pm
BZN
- ORD
1 stop7h 19m
Delta
Sun 10/187:00 am
ORD
- BZN
1 stop8h 58m
Delta
Deal found 7/31![Delta logo]()
$315
Best flights from Montana to IllinoisDiscover carefully curated flight deals from Montana to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 4, 2026.
Discover carefully curated flight deals from Montana to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 4, 2026.
This United Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 9/511:43 am
BIL
- ORD
Nonstop3h 05m
United Airlines
Sat 9/128:40 am
ORD
- BIL
Nonstop3h 22m
United Airlines
Deal found 7/31![United Airlines logo]()
$261
This Delta deal was found by Cheapflights users on 8/3. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1012:58 pm
BIL
- ORD
1 stop8h 02m
Delta
Tue 10/137:35 am
ORD
- BIL
1 stop5h 43m
Delta
Deal found 8/3![Delta logo]()
$281
This Southwest deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/226:55 am
BZN
- MDW
1 stop9h 40m
Southwest
Fri 9/2510:50 am
MDW
- BZN
Nonstop3h 05m
Southwest
Deal found 7/29![Southwest logo]()
$315
This American Airlines deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” 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 10/151:45 pm
MSO
- ORD
Nonstop3h 37m
American Airlines
Tue 10/209:40 am
ORD
- MSO
Nonstop3h 55m
American Airlines
Deal found 7/29![American Airlines logo]()
$319
This Alaska Airlines deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” 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 10/303:49 pm
MSO
- ORD
1 stop7h 10m
Alaska Airlines
Sat 10/317:00 am
ORD
- MSO
1 stop8h 50m
Alaska Airlines
Deal found 7/29![Alaska Airlines logo]()
$369
This Delta deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/512:57 pm
BIL
- ORD
2 stops10h 00m
Delta
Sat 9/123:29 pm
ORD
- BIL
1 stop5h 38m
Delta
Deal found 7/31![Delta logo]()
$286
This United Airlines deal was found by Cheapflights users on 8/2. 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 9/42:30 pm
BZN
- ORD
1 stop7h 16m
United Airlines
Sun 9/64:26 pm
ORD
- BZN
1 stop5h 53m
United Airlines
Deal found 8/2![United Airlines logo]()
$310
This Southwest deal was found by Cheapflights users on 8/3. 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.
Thu 9/312:20 pm
BZN
- MDW
Nonstop2h 55m
Southwest
Sun 9/68:25 am
MDW
- BZN
1 stop8h 10m
Southwest
Deal found 8/3![Southwest logo]()
$326
This American Airlines deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” 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 9/233:26 pm
FCA
- ORD
1 stop7h 04m
American Airlines
Sat 9/269:45 am
ORD
- FCA
Nonstop3h 59m
American Airlines
Deal found 7/29![American Airlines logo]()
$329
This Delta deal was found by Cheapflights users on 8/3. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/1212:58 pm
BIL
- ORD
1 stop7h 49m
Delta
Tue 11/177:35 am
ORD
- BIL
1 stop5h 43m
Delta
Deal found 8/3![Delta logo]()
$312
This United Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 9/174:32 pm
BZN
- ORD
1 stop5h 14m
United Airlines
Mon 9/215:00 am
ORD
- BZN
1 stop5h 39m
United Airlines
Deal found 7/31![United Airlines logo]()
$315
This Southwest deal was found by Cheapflights users on 8/3. 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.
Fri 9/412:20 pm
BZN
- MDW
Nonstop2h 55m
Southwest
Sun 9/64:00 pm
MDW
- BZN
2 stops7h 30m
Southwest
Deal found 8/3![Southwest logo]()
$331
This Alaska Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 1/296:33 am
FCA
- ORD
1 stop6h 39m
Alaska Airlines
Tue 2/23:09 pm
ORD
- FCA
1 stop9h 50m
Alaska Airlines
Deal found 8/1![Alaska Airlines logo]()
$369
This Delta deal was found by Cheapflights users on 8/2. 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.
Fri 10/235:30 am
BZN
- ORD
1 stop5h 25m
Delta
Sun 10/257:00 am
ORD
- BZN
1 stop8h 58m
Delta
Deal found 8/2![Delta logo]()
$315
This United Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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.
Mon 11/92:45 pm
GTF
- ORD
1 stop7h 01m
United Airlines
Sat 11/143:56 pm
ORD
- GTF
1 stop6h 42m
United Airlines
Deal found 8/1![United Airlines logo]()
$328
This Southwest deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1012:20 pm
BZN
- MDW
Nonstop2h 55m
Southwest
Sun 9/135:25 am
MDW
- BZN
1 stop7h 00m
Southwest
Deal found 7/31![Southwest logo]()
$342
This Delta deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 9/206:00 am
BZN
- ORD
1 stop4h 55m
Delta
Wed 9/237:40 pm
ORD
- BZN
1 stop5h 39m
Delta
Deal found 8/1![Delta logo]()
$315
This United Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/282:25 pm
GTF
- ORD
1 stop6h 04m
United Airlines
Mon 8/312:42 pm
ORD
- GTF
1 stop7h 30m
United Airlines
Deal found 8/1![United Airlines logo]()
$328
This Alaska Airlines deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” 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 10/153:49 pm
MSO
- ORD
1 stop7h 10m
Alaska Airlines
Tue 10/203:49 pm
ORD
- MSO
1 stop7h 15m
Alaska Airlines
Deal found 7/30![Alaska Airlines logo]()
$399
This Delta deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 10/236:01 am
BIL
- ORD
2 stops12h 10m
Delta
Tue 10/273:30 pm
ORD
- BIL
1 stop5h 45m
Delta
Deal found 8/1![Delta logo]()
$317
This United Airlines deal was found by Cheapflights users on 8/2. 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 9/112:25 pm
GTF
- ORD
1 stop7h 20m
United Airlines
Sun 9/205:55 am
ORD
- GTF
1 stop8h 34m
United Airlines
Deal found 8/2![United Airlines logo]()
$328
This American Airlines deal was found by Cheapflights users on 8/2. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/41:18 pm
MSO
- STL
1 stop22h 37m
American Airlines
Sun 9/66:36 am
STL
- MSO
1 stop6h 59m
American Airlines
Deal found 8/2![American Airlines logo]()
$447
This Delta deal was found by Cheapflights users on 8/3. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/23:49 pm
BZN
- ORD
1 stop6h 40m
Delta
Wed 9/92:05 pm
ORD
- BZN
2 stops9h 44m
Delta
Deal found 8/3![Delta logo]()
$320
This United Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 9/45:04 pm
FCA
- ORD
1 stop5h 55m
United Airlines
Sun 9/63:50 pm
ORD
- FCA
Nonstop4h 04m
United Airlines
Deal found 7/31![United Airlines logo]()
$329
This Alaska Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 10/67:45 pm
FCA
- ORD
1 stop8h 55m
Alaska Airlines
Fri 10/99:00 am
ORD
- FCA
1 stop11h 05m
Alaska Airlines
Deal found 8/1![Alaska Airlines logo]()
$444
This Delta deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 8/316:00 am
BZN
- ORD
2 stops10h 41m
Delta
Wed 9/26:00 am
ORD
- BZN
2 stops7h 05m
Delta
Deal found 7/31![Delta logo]()
$325
This United Airlines deal was found by Cheapflights users on 8/2. 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.
Sat 9/55:24 pm
MSO
- ORD
1 stop5h 35m
United Airlines
Mon 9/145:00 am
ORD
- MSO
1 stop6h 02m
United Airlines
Deal found 8/2![United Airlines logo]()
$339
This Alaska Airlines deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” 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 10/313:49 pm
MSO
- STL
1 stop7h 10m
Alaska Airlines
Wed 11/47:00 am
STL
- MSO
1 stop9h 34m
Alaska Airlines
Deal found 7/29![Alaska Airlines logo]()
$455
This Delta deal was found by Cheapflights users on 8/3. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/81:13 pm
GTF
- ORD
1 stop7h 34m
Delta
Mon 12/147:35 am
ORD
- GTF
1 stop5h 56m
Delta
Deal found 8/3![Delta logo]()
$328
This United Airlines deal was found by Cheapflights users on 8/3. 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.
Thu 10/88:00 am
BZN
- ORD
Nonstop2h 59m
United Airlines
Thu 10/155:00 am
ORD
- BZN
1 stop5h 46m
United Airlines
Deal found 8/3![United Airlines logo]()
$343
Last-minute flights from Montana to IllinoisDiscover last-minute flight deals from Montana to Illinois. Data last updated August 4, 2026 and is based on user searches.
Discover last-minute flight deals from Montana to Illinois. Data last updated August 4, 2026 and is based on user searches.
This United Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 9/24:30 pm
BZN
- ORD
Nonstop3h 07m
United Airlines
Sat 9/54:15 pm
ORD
- BZN
Nonstop3h 27m
United Airlines
Deal found 7/31![United Airlines logo]()
$295
This United Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 9/27:55 am
BZN
- ORD
Nonstop3h 04m
United Airlines
Fri 9/41:01 pm
ORD
- BZN
Nonstop3h 22m
United Airlines
Deal found 8/1![United Airlines logo]()
$316
This American Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 9/312:55 pm
BZN
- ORD
Nonstop3h 21m
American Airlines
Sun 9/69:45 am
ORD
- BZN
Nonstop3h 20m
American Airlines
Deal found 8/1![American Airlines logo]()
$296
This Delta deal was found by Cheapflights users on 8/3. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/36:00 am
BZN
- ORD
1 stop4h 59m
Delta
Sun 9/67:00 am
ORD
- BZN
1 stop9h 09m
Delta
Deal found 8/3![Delta logo]()
$315
This United Airlines deal was found by Cheapflights users on 8/3. 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.
Fri 9/42:30 pm
BZN
- ORD
1 stop7h 16m
United Airlines
Sun 9/64:26 pm
ORD
- BZN
1 stop5h 53m
United Airlines
Deal found 8/3![United Airlines logo]()
$310
This United Airlines deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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 9/511:43 am
BIL
- ORD
Nonstop3h 05m
United Airlines
Sat 9/128:40 am
ORD
- BIL
Nonstop3h 22m
United Airlines
Deal found 7/31![United Airlines logo]()
$261
This Delta deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/512:57 pm
BIL
- ORD
2 stops10h 00m
Delta
Sat 9/123:29 pm
ORD
- BIL
1 stop5h 38m
Delta
Deal found 7/31![Delta logo]()
$286
This United Airlines deal was found by Cheapflights users on 8/3. 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.
Thu 9/104:32 pm
BZN
- ORD
1 stop5h 14m
United Airlines
Sun 9/134:50 pm
ORD
- BZN
Nonstop3h 27m
United Airlines
Deal found 8/3![United Airlines logo]()
$305
This Southwest deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/145:05 pm
BZN
- MDW
1 stop6h 25m
Southwest
Mon 9/216:15 am
MDW
- BZN
1 stop9h 35m
Southwest
Deal found 7/30![Southwest logo]()
$315
This American Airlines deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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 9/1612:28 pm
BIL
- ORD
Nonstop3h 02m
American Airlines
Wed 9/239:41 am
ORD
- BIL
Nonstop3h 16m
American Airlines
Deal found 8/1![American Airlines logo]()
$309
This Southwest deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/226:55 am
BZN
- MDW
2 stops12h 55m
Southwest
Fri 9/2510:50 am
MDW
- BZN
Nonstop3h 05m
Southwest
Deal found 7/29![Southwest logo]()
$320
This Southwest deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/241:35 pm
BZN
- MDW
1 stop7h 30m
Southwest
Mon 9/2810:50 am
MDW
- BZN
Nonstop3h 05m
Southwest
Deal found 8/1![Southwest logo]()
$305
One-way flights from Montana to IllinoisSearch for one-way flight options from Montana to Illinois. Find affordable one-way fares based on user searches. Data last updated August 4, 2026.
Search for one-way flight options from Montana to Illinois. Find affordable one-way fares based on user searches. Data last updated August 4, 2026.
This Kiwi.com deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” 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.
Sun 9/279:42 pm
BZN
- ORD
1 stop30h 56m
Multiple Airlines
Deal found 7/31![Multiple Airlines logo]()
$140
This Kiwi.com deal was found by Cheapflights users on 8/2. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/53:08 pm
FCA
- ORD
1 stop13h 30m
Multiple Airlines
Deal found 8/2![Multiple Airlines logo]()
$142
This Kiwi.com deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/288:46 pm
FCA
- ORD
2 stops26h 37m
Multiple Airlines
Deal found 7/31![Multiple Airlines logo]()
$143
This Kiwi.com deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/2611:47 am
FCA
- ORD
2 stops21h 14m
Multiple Airlines
Deal found 7/30![Multiple Airlines logo]()
$144
This Kiwi.com deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/285:22 pm
BIL
- ORD
2 stops30h 01m
Multiple Airlines
Deal found 7/31![Multiple Airlines logo]()
$144
This Kiwi.com deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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.
Sun 11/18:39 pm
MSO
- ORD
1 stop14h 18m
Multiple Airlines
Deal found 8/1![Multiple Airlines logo]()
$146
This Southwest deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1012:20 pm
BZN
- MDW
Nonstop2h 55m
Southwest
Deal found 7/30![Southwest logo]()
$148
This Kiwi.com deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” 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.
Sun 9/279:49 pm
MSO
- ORD
1 stop30h 49m
Multiple Airlines
Deal found 8/1![Multiple Airlines logo]()
$148
This American Airlines deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” 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 9/101:33 pm
BZN
- ORD
Nonstop3h 19m
American Airlines
Deal found 7/30![American Airlines logo]()
$148
This Kiwi.com deal was found by Cheapflights users on 8/3. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/211:47 am
FCA
- ORD
1 stop16h 48m
Multiple Airlines
Deal found 8/3![Multiple Airlines logo]()
$150
This Trip.com deal was found by Cheapflights users on 8/3. 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.
Thu 9/242:21 pm
BZN
- ORD
1 stop8h 38m
Alaska Airlines
Deal found 8/3![Alaska Airlines logo]()
$152
This Southwest deal was found by Cheapflights users on 8/2. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/12:00 pm
BZN
- MDW
1 stop4h 50m
Southwest
Deal found 8/2![Southwest logo]()
$153
Find flight deals from Montana to Illinois
Keep the following information in mind while searching for Montana to Illinois flight deals. Data was last updated August 4, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $261 (United Airlines) |
One-way from | $140 (Kiwi.com) |
Popular in | May |
Cheapest in | January |
Average price | $361 |
Good round-trip deal | $420 or less |
Good one-way deal | $244 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Montana 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 August 4, 2026.
Use the filters below to find and compare flights from Montana to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
Quickest round-trip
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Sat 9/5
11:43 am-3:48 pm
Nonstop3h 05m
Chicago O'Hare Intl
Sat 9/12
8:40 am-11:02 am
Nonstop3h 22m
$261
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Sat 10/10
12:58 pm-10:00 pm
1 stop8h 02m
Chicago O'Hare Intl
Tue 10/13
7:35 am-12:18 pm
1 stop5h 43m
$281
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Sat 9/5
12:57 pm-11:57 pm
2 stops10h 00m
Chicago O'Hare Intl
Sat 9/12
3:29 pm-8:07 pm
1 stop5h 38m
$286
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Fri 9/4
2:30 pm-10:46 pm
1 stop7h 16m
Chicago O'Hare Intl
Sun 9/6
4:26 pm-9:19 pm
1 stop5h 53m
$310
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Thu 11/12
12:58 pm-9:47 pm
1 stop7h 49m
Chicago O'Hare Intl
Tue 11/17
7:35 am-12:18 pm
1 stop5h 43m
$312
BozemanChicago
BZN - MDW
BZNMDW
Bozeman Gallatin Field
Tue 9/22
6:55 am-5:35 pm
1 stop9h 40m
Chicago Midway
Fri 9/25
10:50 am-12:55 pm
Nonstop3h 05m
$315
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Thu 9/17
4:32 pm-10:46 pm
1 stop5h 14m
Chicago O'Hare Intl
Mon 9/21
5:00 am-9:39 am
1 stop5h 39m
$315
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Fri 10/23
5:30 am-11:55 am
1 stop5h 25m
Chicago O'Hare Intl
Sun 10/25
7:00 am-2:58 pm
1 stop8h 58m
$315
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Sun 9/20
6:00 am-11:55 am
1 stop4h 55m
Chicago O'Hare Intl
Wed 9/23
7:40 pm-12:19 am
1 stop5h 39m
$315
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Fri 10/23
6:01 am-7:11 pm
2 stops12h 10m
Chicago O'Hare Intl
Tue 10/27
3:30 pm-8:15 pm
1 stop5h 45m
$317
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Montana to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from Montana with our price prediction graph.
BIL-ORD
BZN-ORD
BZN-MDW
FCA-ORD
MSO-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 Montana to Illinois
USMT-USIL
BIL-ORD
BZN-ORD
BZN-MDW
FCA-ORD
What is the cheapest month to book a flight from Montana to Illinois?
Currently, January is the cheapest month in which you can book a flight from Montana to Illinois (average of $310). Flying from Montana to Illinois in November is currently the most expensive (average of $463). 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 MT to IL?
Find hourly flight availability from Montana 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 August 4, 2026.
When flying from Montana to Illinois, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
Weekly flight availability from Montana to Illinois
Explore weekly flight availability from Montana 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 August 4, 2026.
The most flights from USMT to USIL are scheduled on a Monday (12 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (2 on average).
How much does it cost to fly round-trip from Montana to Illinois?
Airfare is typical for this route at the moment.
Montana to Illinois flights typically cost between $295 and $446 in October.The cheapest round-trip price found within the last 5 days was $295 on American Airlines (Oct 2-Oct 4).
How far ahead should I book a flight from Montana to Illinois?
Booking 90 days in advance of your planned departure date is, on average, the best time to get cheap flights from Montana to Illinois. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
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 August 4, 2026.
Get a feel of what it's like to fly with Southwest,Alaska Airlines, andDelta from Montana to Illinois by reading reviews from past customers. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Food
7.0
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Food
7.0
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Food
7.0
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Food
7.0
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Food
7.0
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Food
7.0
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Related info for your journey
Find useful and relevant information for your journey from Montana 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 Montana 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 Montana to Illinois by cabin class
Find flights from Montana to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Montana and Illinois flights
Browse other Montana and Illinois flight options. Last updated on August 4, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Find a return flight route from Illinois
Find the right flight back to Montana after your stay in Illinois
Montana to Illinois flights
Consider these flights traveling from Montana to Illinois.
Top 4 airlines flying from Montana to Illinois
Discover the top 4 airlines that operate flights from Montana 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 August 4, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$215 | Average$401 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$229 | Average$443 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$230 | Average$488 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$350 | Average$467 | FlexibilityNo cancel fee | On-time75% |