$136+ 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 9/8. Fares are subject to change and may not be available on all flights or dates of travel.
BZN — ORD
Jul 20 — Jul 271
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 June 20, 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 June 20, 2026.
This Delta deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/215:40 am
GTF
- ORD
1 stop5h 19m
Delta
Mon 8/248:28 am
ORD
- GTF
2 stops10h 10m
Delta
Deal found 6/18![Delta logo]()
$212
This Delta deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/216:24 am
BIL
- MDW
1 stop5h 45m
Delta
Sat 7/251:49 pm
MDW
- BIL
1 stop7h 10m
Delta
Deal found 6/17![Delta logo]()
$271
This United Airlines deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/16:00 pm
BIL
- ORD
1 stop5h 44m
United Airlines
Sat 8/85:00 am
ORD
- BIL
1 stop5h 35m
United Airlines
Deal found 6/16![United Airlines logo]()
$271
This Delta deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/266:25 am
BIL
- MDW
1 stop5h 42m
Delta
Tue 9/291:47 pm
MDW
- BIL
2 stops9h 37m
Delta
Deal found 6/18![Delta logo]()
$276
This Delta deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/125:20 am
BIL
- ORD
1 stop5h 39m
Delta
Sat 8/153:00 pm
ORD
- BIL
2 stops8h 53m
Delta
Deal found 6/18![Delta logo]()
$276
This American Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/295:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Tue 8/41:49 pm
ORD
- BZN
Nonstop3h 24m
American Airlines
Deal found 6/19![American Airlines logo]()
$285
This American Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/295:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Tue 8/119:45 am
ORD
- BZN
Nonstop3h 20m
American Airlines
Deal found 6/18![American Airlines logo]()
$286
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/62:37 pm
BZN
- ORD
1 stop7h 07m
United Airlines
Mon 11/99:10 am
ORD
- BZN
Nonstop3h 23m
United Airlines
Deal found 6/19![United Airlines logo]()
$291
This United Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/274:40 pm
BIL
- ORD
1 stop6h 19m
United Airlines
Sat 8/298:40 am
ORD
- BIL
Nonstop3h 22m
United Airlines
Deal found 6/18![United Airlines logo]()
$292
This United Airlines deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/174:23 pm
BZN
- ORD
Nonstop3h 07m
United Airlines
Tue 9/225:00 am
ORD
- BZN
1 stop5h 39m
United Airlines
Deal found 6/16![United Airlines logo]()
$295
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/286:00 pm
BIL
- ORD
1 stop5h 44m
United Airlines
Sat 8/15:00 am
ORD
- BIL
1 stop5h 35m
United Airlines
Deal found 6/19![United Airlines logo]()
$297
This Delta deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/171:15 pm
GTF
- ORD
1 stop7h 32m
Delta
Mon 9/2111:20 am
ORD
- GTF
2 stops12h 22m
Delta
Deal found 6/19![Delta logo]()
$298
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 June 20, 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 June 20, 2026.
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/234:24 pm
BZN
- ORD
Nonstop3h 16m
United Airlines
Sun 7/265:00 am
ORD
- BZN
1 stop5h 29m
United Airlines
Deal found 6/19![United Airlines logo]()
$295
This Delta deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/2412:13 pm
BZN
- ORD
1 stop8h 16m
Delta
Mon 7/276:55 am
ORD
- BZN
1 stop8h 40m
Delta
Deal found 6/15![Delta logo]()
$305
This Southwest deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/161:50 pm
BZN
- MDW
1 stop8h 40m
Southwest
Sun 7/196:10 am
MDW
- BZN
1 stop14h 30m
Southwest
Deal found 6/15![Southwest logo]()
$336
This Alaska Airlines deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/104:16 pm
MSO
- ORD
1 stop6h 43m
Alaska Airlines
Mon 9/147:00 pm
ORD
- MSO
1 stop29h 01m
Alaska Airlines
Deal found 6/17![Alaska Airlines logo]()
$452
This United Airlines deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/262:29 pm
BIL
- ORD
1 stop6h 00m
United Airlines
Sun 8/305:00 am
ORD
- BIL
1 stop5h 41m
United Airlines
Deal found 6/16![United Airlines logo]()
$302
This Delta deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/62:00 pm
BZN
- MDW
1 stop7h 10m
Delta
Mon 11/99:55 am
MDW
- BZN
2 stops9h 00m
Delta
Deal found 6/19![Delta logo]()
$310
This Delta deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/181:15 pm
GTF
- ORD
1 stop7h 32m
Delta
Sun 9/207:45 am
ORD
- GTF
1 stop5h 50m
Delta
Deal found 6/15![Delta logo]()
$318
This Southwest deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/234:30 pm
BZN
- MDW
2 stops7h 35m
Southwest
Sun 7/265:00 am
MDW
- BZN
1 stop7h 30m
Southwest
Deal found 6/15![Southwest logo]()
$360
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/294:24 pm
BZN
- ORD
Nonstop3h 16m
United Airlines
Mon 8/35:00 am
ORD
- BZN
1 stop5h 37m
United Airlines
Deal found 6/19![United Airlines logo]()
$336
This Delta deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/41:10 pm
GTF
- ORD
1 stop7h 43m
Delta
Sun 11/81:15 pm
ORD
- GTF
2 stops10h 38m
Delta
Deal found 6/17![Delta logo]()
$324
This United Airlines deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/284:29 pm
BZN
- ORD
1 stop7h 15m
United Airlines
Thu 7/308:15 pm
ORD
- BZN
Nonstop3h 28m
United Airlines
Deal found 6/17![United Airlines logo]()
$348
This Southwest deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/171:50 pm
BZN
- MDW
2 stops9h 50m
Southwest
Sun 7/196:10 am
MDW
- BZN
1 stop14h 30m
Southwest
Deal found 6/17![Southwest logo]()
$392
This Delta deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/1412:55 pm
HLN
- ORD
1 stop7h 35m
Delta
Mon 8/247:48 am
ORD
- HLN
1 stop5h 27m
Delta
Deal found 6/19![Delta logo]()
$329
This United Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/135:04 pm
FCA
- ORD
1 stop5h 55m
United Airlines
Mon 8/178:40 am
ORD
- FCA
Nonstop3h 47m
United Airlines
Deal found 6/18![United Airlines logo]()
$352
This Alaska Airlines deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/295:09 pm
HLN
- ORD
2 stops26h 20m
Alaska Airlines
Tue 8/48:20 pm
ORD
- HLN
1 stop21h 12m
Alaska Airlines
Deal found 6/15![Alaska Airlines logo]()
$469
This Southwest deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/306:40 am
BZN
- MDW
Nonstop2h 50m
Southwest
Sat 7/412:40 pm
MDW
- BZN
1 stop6h 50m
Southwest
Deal found 6/15![Southwest logo]()
$395
This Delta deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/62:00 pm
BZN
- MDW
1 stop7h 10m
Delta
Sun 11/86:00 am
MDW
- BZN
1 stop8h 16m
Delta
Deal found 6/19![Delta logo]()
$332
This United Airlines deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1012:25 pm
MSO
- ORD
Nonstop3h 40m
United Airlines
Mon 9/145:00 am
ORD
- MSO
1 stop5h 57m
United Airlines
Deal found 6/17![United Airlines logo]()
$358
This Expedia deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/145:41 pm
MSO
- STL
1 stop21h 56m
Alaska Airlines
Tue 9/16:00 am
STL
- MSO
2 stops18h 01m
Alaska Airlines
Deal found 6/16![Alaska Airlines logo]()
$485
This Delta deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/106:26 am
BIL
- MDW
1 stop5h 44m
Delta
Mon 8/177:25 pm
MDW
- BIL
1 stop5h 05m
Delta
Deal found 6/17![Delta logo]()
$333
This Southwest deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/101:50 pm
BZN
- MDW
1 stop8h 40m
Southwest
Mon 7/1311:00 am
MDW
- BZN
Nonstop3h 10m
Southwest
Deal found 6/16![Southwest logo]()
$424
This United Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/182:29 pm
BIL
- ORD
1 stop6h 31m
United Airlines
Sun 9/205:00 am
ORD
- BIL
1 stop5h 41m
United Airlines
Deal found 6/18![United Airlines logo]()
$362
This Delta deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/95:45 am
BIL
- ORD
1 stop5h 40m
Delta
Thu 11/193:50 pm
ORD
- BIL
1 stop4h 58m
Delta
Deal found 6/16![Delta logo]()
$333
This Delta deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/128:00 am
MSO
- MDW
1 stop7h 50m
Delta
Sun 11/159:55 am
MDW
- MSO
2 stops8h 32m
Delta
Deal found 6/17![Delta logo]()
$334
This United Airlines deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/24:24 pm
BZN
- ORD
Nonstop3h 16m
United Airlines
Mon 7/69:10 am
ORD
- BZN
Nonstop3h 34m
United Airlines
Deal found 6/17![United Airlines logo]()
$385
This Southwest deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/26:35 am
BZN
- MDW
1 stop5h 50m
Southwest
Wed 7/85:50 pm
MDW
- BZN
2 stops8h 00m
Southwest
Deal found 6/15![Southwest logo]()
$468
This Alaska Airlines deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/105:09 pm
HLN
- ORD
1 stop12h 11m
Alaska Airlines
Mon 7/136:00 am
ORD
- HLN
1 stop11h 32m
Alaska Airlines
Deal found 6/17![Alaska Airlines logo]()
$585
This Delta deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/298:00 am
MSO
- MDW
1 stop7h 50m
Delta
Mon 11/29:55 am
MDW
- MSO
2 stops8h 32m
Delta
Deal found 6/15![Delta logo]()
$334
This United Airlines deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/304:24 pm
BZN
- ORD
Nonstop3h 16m
United Airlines
Sat 7/49:10 am
ORD
- BZN
Nonstop3h 34m
United Airlines
Deal found 6/15![United Airlines logo]()
$385
This Delta deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/283:55 pm
BZN
- ORD
1 stop4h 52m
Delta
Sat 8/297:48 am
ORD
- BZN
1 stop5h 17m
Delta
Deal found 6/18![Delta logo]()
$342
Last-minute flights from Montana to IllinoisDiscover last-minute flight deals from Montana to Illinois. Data last updated June 20, 2026 and is based on user searches.
Discover last-minute flight deals from Montana to Illinois. Data last updated June 20, 2026 and is based on user searches.
This United Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/116:00 pm
BIL
- ORD
1 stop5h 44m
United Airlines
Sat 7/185:00 am
ORD
- BIL
1 stop5h 35m
United Airlines
Deal found 6/18![United Airlines logo]()
$334
This United Airlines deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/154:24 pm
BZN
- ORD
Nonstop3h 16m
United Airlines
Mon 7/208:15 pm
ORD
- BZN
Nonstop3h 28m
United Airlines
Deal found 6/15![United Airlines logo]()
$334
This Delta deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/163:54 pm
BZN
- ORD
1 stop6h 44m
Delta
Mon 7/206:55 am
ORD
- BZN
1 stop8h 40m
Delta
Deal found 6/15![Delta logo]()
$305
This Delta deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/216:24 am
BIL
- MDW
1 stop5h 45m
Delta
Sat 7/251:49 pm
MDW
- BIL
1 stop7h 10m
Delta
Deal found 6/17![Delta logo]()
$271
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/234:24 pm
BZN
- ORD
Nonstop3h 16m
United Airlines
Sun 7/265:00 am
ORD
- BZN
1 stop5h 29m
United Airlines
Deal found 6/19![United Airlines logo]()
$295
This Southwest deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/231:50 pm
BZN
- MDW
1 stop8h 40m
Southwest
Sun 7/265:00 am
MDW
- BZN
1 stop7h 30m
Southwest
Deal found 6/15![Southwest logo]()
$305
This American Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/235:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Sat 8/812:10 pm
ORD
- BZN
1 stop9h 27m
American Airlines
Deal found 6/18![American Airlines logo]()
$332
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/286:00 pm
BIL
- ORD
1 stop5h 44m
United Airlines
Sat 8/15:00 am
ORD
- BIL
1 stop5h 35m
United Airlines
Deal found 6/19![United Airlines logo]()
$297
This United Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/284:29 pm
BZN
- ORD
1 stop7h 15m
United Airlines
Sat 8/18:15 pm
ORD
- BZN
Nonstop3h 28m
United Airlines
Deal found 6/19![United Airlines logo]()
$309
This American Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/285:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Wed 8/59:45 am
ORD
- BZN
Nonstop3h 20m
American Airlines
Deal found 6/18![American Airlines logo]()
$322
This American Airlines deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/295:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Tue 8/41:49 pm
ORD
- BZN
Nonstop3h 24m
American Airlines
Deal found 6/19![American Airlines logo]()
$285
This American Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/295:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Tue 8/119:45 am
ORD
- BZN
Nonstop3h 20m
American Airlines
Deal found 6/18![American Airlines logo]()
$286
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 June 20, 2026.
Search for one-way flight options from Montana to Illinois. Find affordable one-way fares based on user searches. Data last updated June 20, 2026.
This United Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/84:07 pm
BIL
- ORD
1 stop5h 39m
United Airlines
Deal found 6/18![United Airlines logo]()
$136
This Kiwi.com deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/2010:19 am
GTF
- ORD
1 stop18h 18m
Multiple Airlines
Deal found 6/16![Multiple Airlines logo]()
$143
This Southwest deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/296:40 am
BZN
- MDW
Nonstop2h 50m
Southwest
Deal found 6/17![Southwest logo]()
$143
This American Airlines deal was found by Cheapflights users on 6/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/315:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Deal found 6/18![American Airlines logo]()
$143
This United Airlines deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/192:30 pm
BZN
- ORD
1 stop7h 16m
United Airlines
Deal found 6/17![United Airlines logo]()
$148
This Delta deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/156:10 am
BZN
- MDW
1 stop5h 57m
Delta
Deal found 6/16![Delta logo]()
$153
This Delta deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/146:00 am
BZN
- ORD
1 stop4h 59m
Delta
Deal found 6/16![Delta logo]()
$153
This Delta deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/155:45 am
BZN
- MDW
2 stops10h 05m
Delta
Deal found 6/16![Delta logo]()
$158
This Delta deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/158:25 am
BZN
- ORD
2 stops12h 22m
Delta
Deal found 6/16![Delta logo]()
$158
This Kiwi.com deal was found by Cheapflights users on 6/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/145:22 pm
BIL
- ORD
1 stop11h 20m
Multiple Airlines
Deal found 6/20![Multiple Airlines logo]()
$162
This Southwest deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/412:20 pm
BZN
- MDW
Nonstop2h 55m
Southwest
Deal found 6/17![Southwest logo]()
$169
This Kiwi.com deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/139:42 pm
BZN
- ORD
1 stop13h 15m
Multiple Airlines
Deal found 6/16![Multiple Airlines logo]()
$169
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 June 20, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $212 (Delta) |
One-way from | $136 (United Airlines) |
Popular in | May |
Cheapest in | September |
Average price | $408 |
Good round-trip deal | $348 or less |
Good one-way deal | $201 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 June 20, 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
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Thu 7/23
4:24 pm-8:40 pm
Nonstop3h 16m
Chicago O'Hare Intl
Sun 7/26
5:00 am-9:29 am
1 stop5h 29m
$295
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Wed 8/26
2:29 pm-9:29 pm
1 stop6h 00m
Chicago O'Hare Intl
Sun 8/30
5:00 am-9:41 am
1 stop5h 41m
$302
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Fri 7/24
12:13 pm-9:29 pm
1 stop8h 16m
Chicago O'Hare Intl
Mon 7/27
6:55 am-2:35 pm
1 stop8h 40m
$305
BozemanChicago
BZN - MDW
BZNMDW
Bozeman Gallatin Field
Fri 11/6
2:00 pm-10:10 pm
1 stop7h 10m
Chicago Midway
Mon 11/9
9:55 am-5:55 pm
2 stops9h 00m
$310
Great FallsChicago
GTF - ORD
GTFORD
Great Falls
Fri 9/18
1:15 pm-9:47 pm
1 stop7h 32m
Chicago O'Hare Intl
Sun 9/20
7:45 am-12:35 pm
1 stop5h 50m
$318
Great FallsChicago
GTF - ORD
GTFORD
Great Falls
Wed 11/4
1:10 pm-9:53 pm
1 stop7h 43m
Chicago O'Hare Intl
Sun 11/8
1:15 pm-10:53 pm
2 stops10h 38m
$324
HelenaChicago
HLN - ORD
HLNORD
Helena
Fri 8/14
12:55 pm-9:30 pm
1 stop7h 35m
Chicago O'Hare Intl
Mon 8/24
7:48 am-12:15 pm
1 stop5h 27m
$329
BozemanChicago
BZN - MDW
BZNMDW
Bozeman Gallatin Field
Fri 11/6
2:00 pm-10:10 pm
1 stop7h 10m
Chicago Midway
Sun 11/8
6:00 am-1:16 pm
1 stop8h 16m
$332
BillingsChicago
BIL - MDW
BILMDW
Billings Logan Intl
Mon 8/10
6:26 am-1:10 pm
1 stop5h 44m
Chicago Midway
Mon 8/17
7:25 pm-11:30 pm
1 stop5h 05m
$333
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Mon 11/9
5:45 am-12:25 pm
1 stop5h 40m
Chicago O'Hare Intl
Thu 11/19
3:50 pm-7:48 pm
1 stop4h 58m
$333
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-MDW
BZN-ORD
BIL-ORD
BZN-MDW
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-MDW
BZN-ORD
BIL-ORD
BZN-MDW
What is the cheapest month to book a flight from Montana to Illinois?
Currently, July is the cheapest month in which you can book a flight from Montana to Illinois (average of $129). Flying from Montana to Illinois in November is currently the most expensive (average of $249). 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 June 20, 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 June 20, 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 (3 on average).
How much does it cost to fly round-trip from Montana to Illinois?
How far ahead should I book a flight from Montana to Illinois?
Booking 76 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 June 20, 2026.
Get a feel of what it's like to fly with Alaska Airlines,Southwest, 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.
Entertainment
7.0
Boarding
8.1
Overall
7.9
Comfort
7.8
Crew
8.5
Food
7.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Entertainment
7.0
Boarding
8.1
Overall
7.9
Comfort
7.8
Crew
8.5
Food
7.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Entertainment
7.0
Boarding
8.1
Overall
7.9
Comfort
7.8
Crew
8.5
Food
7.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Entertainment
7.0
Boarding
8.1
Overall
7.9
Comfort
7.8
Crew
8.5
Food
7.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Entertainment
7.0
Boarding
8.1
Overall
7.9
Comfort
7.8
Crew
8.5
Food
7.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Entertainment
7.0
Boarding
8.1
Overall
7.9
Comfort
7.8
Crew
8.5
Food
7.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
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.
Browse thousands of different options on Cheapflights for your next trip
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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 June 20, 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 June 20, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$129 | Average$488 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$166 | Average$467 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$191 | Average$370 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$229 | Average$447 | FlexibilityNo cancel fee | On-time69% |