$133+ 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 10/28. Fares are subject to change and may not be available on all flights or dates of travel.
BZN — ORD
May 31 — Jun 71
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 May 1, 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 May 1, 2026.
This American Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/2111:48 am
BZN
- STL
1 stop6h 48m
American Airlines
Wed 5/278:36 am
STL
- BZN
1 stop7h 50m
American Airlines
Deal found 4/28![American Airlines logo]()
$271
This United Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 5/276:00 pm
BIL
- ORD
1 stop5h 44m
United Airlines
Sat 5/307:05 am
ORD
- BIL
1 stop7h 17m
United Airlines
Deal found 4/27![United Airlines logo]()
$271
This Delta deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 7/115:20 am
BIL
- ORD
1 stop5h 39m
Delta
Tue 7/143:55 pm
ORD
- BIL
2 stops7h 55m
Delta
Deal found 4/28![Delta logo]()
$276
This American Airlines deal was found by Cheapflights users on 4/30. 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.
Wed 7/295:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Tue 8/41:49 pm
ORD
- BZN
Nonstop3h 24m
American Airlines
Deal found 4/30![American Airlines logo]()
$285
This American Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/284:57 pm
BZN
- ORD
Nonstop3h 28m
American Airlines
Sun 5/3110:10 am
ORD
- BZN
Nonstop3h 18m
American Airlines
Deal found 4/28![American Airlines logo]()
$286
This American Airlines deal was found by Cheapflights users on 4/29. 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.
Fri 9/1112:17 pm
BIL
- ORD
Nonstop2h 53m
American Airlines
Mon 9/149:40 am
ORD
- BIL
Nonstop3h 05m
American Airlines
Deal found 4/29![American Airlines logo]()
$289
This Alaska Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 9/13:32 pm
BZN
- ORD
1 stop7h 09m
Alaska Airlines
Wed 9/27:00 am
ORD
- BZN
1 stop7h 24m
Alaska Airlines
Deal found 4/27![Alaska Airlines logo]()
$291
This Delta deal was found by Cheapflights users on 5/1. 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.
Wed 5/276:30 am
BIL
- ORD
1 stop7h 27m
Delta
Wed 6/32:00 pm
ORD
- BIL
2 stops10h 14m
Delta
Deal found 5/1![Delta logo]()
$295
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 6/24:10 pm
BIL
- ORD
1 stop5h 39m
United Airlines
Fri 6/57:52 pm
ORD
- BIL
Nonstop3h 23m
United Airlines
Deal found 4/28![United Airlines logo]()
$297
This United Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 6/22:26 pm
BZN
- ORD
1 stop7h 23m
United Airlines
Mon 6/155:00 am
ORD
- BZN
1 stop5h 37m
United Airlines
Deal found 4/27![United Airlines logo]()
$300
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/2312:45 pm
BZN
- STL
1 stop7h 05m
United Airlines
Sat 5/305:29 pm
STL
- BZN
1 stop6h 14m
United Airlines
Deal found 4/28![United Airlines logo]()
$301
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 6/1010:33 am
BZN
- STL
1 stop5h 00m
United Airlines
Fri 6/125:10 am
STL
- BZN
1 stop5h 27m
United Airlines
Deal found 4/28![United Airlines logo]()
$302
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 May 1, 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 May 1, 2026.
This United Airlines deal was found by Cheapflights users on 4/29. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/174:29 pm
BZN
- STL
1 stop6h 28m
United Airlines
Tue 6/235:10 am
STL
- BZN
1 stop5h 27m
United Airlines
Deal found 4/29![United Airlines logo]()
$271
This Delta deal was found by Cheapflights users on 5/1. 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.
Wed 5/276:30 am
BIL
- ORD
1 stop7h 27m
Delta
Wed 6/32:00 pm
ORD
- BIL
2 stops10h 14m
Delta
Deal found 5/1![Delta logo]()
$295
This Alaska Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 10/244:08 pm
HLN
- STL
1 stop6h 51m
Alaska Airlines
Wed 10/287:00 am
STL
- HLN
1 stop9h 31m
Alaska Airlines
Deal found 4/28![Alaska Airlines logo]()
$329
This American Airlines deal was found by Cheapflights users on 4/26. Clicking the “Pick Dates” 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 5/2912:25 pm
FCA
- ORD
1 stop8h 45m
American Airlines
Tue 6/26:00 am
ORD
- FCA
1 stop10h 00m
American Airlines
Deal found 4/26![American Airlines logo]()
$329
This Southwest deal was found by Cheapflights users on 4/29. 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.
Wed 8/122:00 pm
BZN
- MDW
1 stop4h 45m
Southwest
Wed 8/196:00 pm
MDW
- BZN
1 stop5h 25m
Southwest
Deal found 4/29![Southwest logo]()
$352
This Kiwi.com deal was found by Cheapflights users on 5/1. 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.
Mon 6/1510:18 am
GTF
- ORD
1 stop17h 49m
Multiple Airlines
Thu 6/1812:31 pm
ORD
- GTF
2 stops21h 57m
Multiple Airlines
Deal found 5/1![Multiple Airlines logo]()
$390
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/274:10 pm
BIL
- ORD
1 stop7h 34m
United Airlines
Sat 5/305:00 am
ORD
- BIL
1 stop5h 35m
United Airlines
Deal found 4/28![United Airlines logo]()
$290
This Delta deal was found by Cheapflights users on 4/29. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/125:45 am
BZN
- ORD
1 stop5h 36m
Delta
Fri 8/216:59 pm
ORD
- BZN
1 stop6h 00m
Delta
Deal found 4/29![Delta logo]()
$305
This United Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 8/134:05 pm
BZN
- ORD
Nonstop3h 16m
United Airlines
Tue 8/182:33 pm
ORD
- BZN
1 stop7h 34m
United Airlines
Deal found 4/27![United Airlines logo]()
$295
This Alaska Airlines deal was found by Cheapflights users on 4/26. Clicking the “Pick Dates” 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 10/144:13 pm
MSO
- ORD
1 stop6h 46m
Alaska Airlines
Sat 10/176:00 am
ORD
- MSO
1 stop7h 32m
Alaska Airlines
Deal found 4/26![Alaska Airlines logo]()
$329
This Delta deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 7/1312:13 pm
BZN
- ORD
1 stop5h 44m
Delta
Fri 7/177:40 pm
ORD
- BZN
1 stop5h 43m
Delta
Deal found 4/28![Delta logo]()
$305
This United Airlines deal was found by Cheapflights users on 4/29. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/15:38 pm
BZN
- ORD
1 stop6h 06m
United Airlines
Thu 6/48:15 pm
ORD
- BZN
Nonstop3h 28m
United Airlines
Deal found 4/29![United Airlines logo]()
$295
This Alaska Airlines deal was found by Cheapflights users on 4/26. Clicking the “Pick Dates” 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 10/272:16 pm
MSO
- ORD
1 stop8h 43m
Alaska Airlines
Fri 10/308:00 am
ORD
- MSO
1 stop8h 23m
Alaska Airlines
Deal found 4/26![Alaska Airlines logo]()
$329
This Delta deal was found by Cheapflights users on 4/30. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/238:25 am
BZN
- ORD
2 stops12h 23m
Delta
Sun 7/267:45 am
ORD
- BZN
1 stop7h 48m
Delta
Deal found 4/30![Delta logo]()
$310
This Southwest deal was found by Cheapflights users on 4/30. 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 8/2412:20 pm
BZN
- MDW
Nonstop2h 55m
Southwest
Wed 8/2610:05 am
MDW
- BZN
Nonstop3h 10m
Southwest
Deal found 4/30![Southwest logo]()
$390
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 6/24:10 pm
BIL
- ORD
1 stop5h 39m
United Airlines
Fri 6/57:52 pm
ORD
- BIL
Nonstop3h 23m
United Airlines
Deal found 4/28![United Airlines logo]()
$297
This Alaska Airlines deal was found by Cheapflights users on 4/30. 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.
Tue 6/211:33 am
FCA
- ORD
1 stop6h 30m
Alaska Airlines
Sat 6/65:52 pm
ORD
- FCA
1 stop7h 06m
Alaska Airlines
Deal found 4/30![Alaska Airlines logo]()
$329
This Delta deal was found by Cheapflights users on 4/29. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/36:00 am
BZN
- ORD
2 stops11h 05m
Delta
Wed 6/107:37 pm
ORD
- BZN
1 stop5h 46m
Delta
Deal found 4/29![Delta logo]()
$310
This Southwest deal was found by Cheapflights users on 4/29. 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.
Wed 6/171:30 pm
BZN
- STL
1 stop7h 20m
Southwest
Tue 6/233:10 pm
STL
- BZN
2 stops8h 30m
Southwest
Deal found 4/29![Southwest logo]()
$394
This United Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 8/202:37 pm
BZN
- ORD
1 stop7h 04m
United Airlines
Tue 8/254:35 pm
ORD
- BZN
1 stop5h 32m
United Airlines
Deal found 4/27![United Airlines logo]()
$300
This Delta deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 7/25:15 am
BZN
- ORD
2 stops10h 47m
Delta
Sun 7/57:45 am
ORD
- BZN
1 stop7h 50m
Delta
Deal found 4/28![Delta logo]()
$310
This Alaska Airlines deal was found by Cheapflights users on 5/1. 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.
Sat 5/237:59 pm
BZN
- ORD
1 stop9h 21m
Alaska Airlines
Fri 5/293:28 pm
ORD
- BZN
1 stop8h 14m
Alaska Airlines
Deal found 5/1![Alaska Airlines logo]()
$365
This Southwest deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 6/117:15 pm
BZN
- MDW
1 stop9h 10m
Southwest
Mon 6/156:25 pm
MDW
- BZN
2 stops7h 45m
Southwest
Deal found 4/27![Southwest logo]()
$415
This Delta deal was found by Cheapflights users on 4/30. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/245:45 am
BZN
- MDW
2 stops11h 46m
Delta
Wed 8/261:05 pm
MDW
- BZN
2 stops11h 48m
Delta
Deal found 4/30![Delta logo]()
$315
This United Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 5/205:08 pm
MSO
- ORD
1 stop5h 48m
United Airlines
Mon 5/258:40 am
ORD
- MSO
Nonstop3h 52m
United Airlines
Deal found 4/27![United Airlines logo]()
$319
This Alaska Airlines deal was found by Cheapflights users on 4/26. Clicking the “Pick Dates” 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 10/164:13 pm
MSO
- ORD
1 stop6h 46m
Alaska Airlines
Mon 10/195:55 pm
ORD
- MSO
1 stop7h 24m
Alaska Airlines
Deal found 4/26![Alaska Airlines logo]()
$374
This Delta deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 6/191:20 pm
GTF
- ORD
1 stop7h 37m
Delta
Sat 6/207:45 am
ORD
- GTF
1 stop5h 55m
Delta
Deal found 4/27![Delta logo]()
$318
This Southwest deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/216:15 am
BZN
- STL
2 stops8h 35m
Southwest
Wed 5/276:30 pm
STL
- BZN
1 stop6h 45m
Southwest
Deal found 4/28![Southwest logo]()
$429
This United Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 5/205:08 pm
MSO
- ORD
1 stop6h 50m
United Airlines
Sun 5/246:00 am
ORD
- MSO
1 stop8h 24m
United Airlines
Deal found 4/27![United Airlines logo]()
$329
This Alaska Airlines deal was found by Cheapflights users on 4/29. 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.
Tue 10/612:51 pm
FCA
- ORD
1 stop10h 08m
Alaska Airlines
Mon 10/126:00 am
ORD
- FCA
1 stop7h 14m
Alaska Airlines
Deal found 4/29![Alaska Airlines logo]()
$374
Last-minute flights from Montana to IllinoisDiscover last-minute flight deals from Montana to Illinois. Data last updated May 1, 2026 and is based on user searches.
Discover last-minute flight deals from Montana to Illinois. Data last updated May 1, 2026 and is based on user searches.
This American Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/2111:48 am
BZN
- STL
1 stop6h 48m
American Airlines
Wed 5/278:36 am
STL
- BZN
1 stop7h 50m
American Airlines
Deal found 4/28![American Airlines logo]()
$271
This American Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 5/214:45 pm
FCA
- ORD
Nonstop3h 49m
American Airlines
Wed 5/271:16 pm
ORD
- FCA
Nonstop3h 47m
American Airlines
Deal found 4/27![American Airlines logo]()
$311
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/2212:35 pm
FCA
- ORD
Nonstop3h 30m
United Airlines
Mon 5/258:40 am
ORD
- FCA
Nonstop3h 49m
United Airlines
Deal found 4/28![United Airlines logo]()
$309
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/226:00 pm
BIL
- ORD
1 stop5h 44m
United Airlines
Sun 5/245:00 am
ORD
- BIL
1 stop5h 34m
United Airlines
Deal found 4/28![United Airlines logo]()
$309
This American Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/2212:42 pm
BIL
- ORD
Nonstop3h 02m
American Airlines
Sun 5/249:45 am
ORD
- BIL
Nonstop3h 27m
American Airlines
Deal found 4/28![American Airlines logo]()
$314
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/2312:45 pm
BZN
- STL
1 stop7h 05m
United Airlines
Sat 5/305:29 pm
STL
- BZN
1 stop6h 14m
United Airlines
Deal found 4/28![United Airlines logo]()
$301
This United Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 5/276:00 pm
BIL
- ORD
1 stop5h 44m
United Airlines
Sat 5/307:05 am
ORD
- BIL
1 stop7h 17m
United Airlines
Deal found 4/27![United Airlines logo]()
$271
This Delta deal was found by Cheapflights users on 5/1. 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.
Wed 5/276:30 am
BIL
- ORD
1 stop7h 27m
Delta
Wed 6/32:00 pm
ORD
- BIL
2 stops10h 14m
Delta
Deal found 5/1![Delta logo]()
$295
This American Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/284:57 pm
BZN
- ORD
Nonstop3h 28m
American Airlines
Sun 5/3110:10 am
ORD
- BZN
Nonstop3h 18m
American Airlines
Deal found 4/28![American Airlines logo]()
$286
This American Airlines deal was found by Cheapflights users on 4/30. 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.
Sun 5/314:57 pm
BZN
- ORD
Nonstop3h 28m
American Airlines
Tue 6/29:40 am
ORD
- BZN
1 stop7h 13m
American Airlines
Deal found 4/30![American Airlines logo]()
$295
This Delta deal was found by Cheapflights users on 4/29. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/315:35 am
BZN
- ORD
1 stop5h 17m
Delta
Tue 6/25:19 pm
ORD
- BZN
2 stops7h 40m
Delta
Deal found 4/29![Delta logo]()
$310
This United Airlines deal was found by Cheapflights users on 5/1. 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.
Sun 5/318:00 am
BZN
- ORD
Nonstop3h 02m
United Airlines
Tue 6/28:15 pm
ORD
- BZN
Nonstop3h 28m
United Airlines
Deal found 5/1![United Airlines logo]()
$311
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 May 1, 2026.
Search for one-way flight options from Montana to Illinois. Find affordable one-way fares based on user searches. Data last updated May 1, 2026.
This Alaska Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 10/2811:16 am
BZN
- ORD
1 stop7h 39m
Alaska Airlines
Deal found 4/28![Alaska Airlines logo]()
$133
This American Airlines deal was found by Cheapflights users on 4/30. 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.
Tue 7/215:03 pm
BZN
- STL
1 stop6h 13m
American Airlines
Deal found 4/30![American Airlines logo]()
$136
This Southwest deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 6/246:40 am
BZN
- MDW
Nonstop2h 50m
Southwest
Deal found 4/27![Southwest logo]()
$143
This American Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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.
Sat 7/185:03 pm
BZN
- ORD
Nonstop3h 27m
American Airlines
Deal found 4/28![American Airlines logo]()
$143
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 8/192:37 pm
BZN
- ORD
1 stop7h 04m
United Airlines
Deal found 4/28![United Airlines logo]()
$148
This Alaska Airlines deal was found by Cheapflights users on 4/29. 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.
Sun 5/178:00 am
BZN
- STL
1 stop9h 45m
Alaska Airlines
Deal found 4/29![Alaska Airlines logo]()
$150
This Kiwi.com deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/2510:36 am
FCA
- ORD
2 stops44h 19m
Multiple Airlines
Deal found 4/28![Multiple Airlines logo]()
$151
This Kiwi.com deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 5/2510:36 am
FCA
- MDW
2 stops34h 26m
Multiple Airlines
Deal found 4/28![Multiple Airlines logo]()
$151
This Delta deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” 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 10/2412:50 pm
BZN
- MDW
1 stop7h 55m
Delta
Deal found 4/27![Delta logo]()
$153
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” 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 8/184:22 pm
BZN
- ORD
1 stop5h 19m
United Airlines
Deal found 4/28![United Airlines logo]()
$153
This Delta deal was found by Cheapflights users on 4/29. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/305:45 am
BZN
- STL
1 stop6h 36m
Delta
Deal found 4/29![Delta logo]()
$159
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/1812:09 pm
BZN
- ORD
3 stops55h 23m
Multiple Airlines
Deal found 4/29![Multiple Airlines logo]()
$164
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 May 1, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $271 (American Airlines) |
One-way from | $133 (Alaska Airlines) |
Popular in | May |
Cheapest in | September |
Average price | $403 |
Good round-trip deal | $379 or less |
Good one-way deal | $185 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 May 1, 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
BozemanSt. Louis
BZN - STL
BZNSTL
Bozeman Gallatin Field
Wed 6/17
4:29 pm-11:57 pm
1 stop6h 28m
Lambert-St Louis
Tue 6/23
5:10 am-9:37 am
1 stop5h 27m
$271
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Wed 5/27
4:10 pm-12:44 am
1 stop7h 34m
Chicago O'Hare Intl
Sat 5/30
5:00 am-9:35 am
1 stop5h 35m
$290
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Wed 5/27
6:30 am-2:57 pm
1 stop7h 27m
Chicago O'Hare Intl
Wed 6/3
2:00 pm-11:14 pm
2 stops10h 14m
$295
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Thu 8/13
4:05 pm-8:21 pm
Nonstop3h 16m
Chicago O'Hare Intl
Tue 8/18
2:33 pm-9:07 pm
1 stop7h 34m
$295
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Mon 6/1
5:38 pm-12:44 am
1 stop6h 06m
Chicago O'Hare Intl
Thu 6/4
8:15 pm-10:43 pm
Nonstop3h 28m
$295
BillingsChicago
BIL - ORD
BILORD
Billings Logan Intl
Tue 6/2
4:10 pm-10:49 pm
1 stop5h 39m
Chicago O'Hare Intl
Fri 6/5
7:52 pm-10:15 pm
Nonstop3h 23m
$297
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Thu 8/20
2:37 pm-10:41 pm
1 stop7h 04m
Chicago O'Hare Intl
Tue 8/25
4:35 pm-9:07 pm
1 stop5h 32m
$300
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Wed 8/12
5:45 am-12:21 pm
1 stop5h 36m
Chicago O'Hare Intl
Fri 8/21
6:59 pm-11:59 pm
1 stop6h 00m
$305
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Mon 7/13
12:13 pm-6:57 pm
1 stop5h 44m
Chicago O'Hare Intl
Fri 7/17
7:40 pm-12:23 am
1 stop5h 43m
$305
BozemanChicago
BZN - ORD
BZNORD
Bozeman Gallatin Field
Thu 7/23
8:25 am-9:48 pm
2 stops12h 23m
Chicago O'Hare Intl
Sun 7/26
7:45 am-2:33 pm
1 stop7h 48m
$310
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.
BZN-STL
BIL-ORD
BZN-ORD
FCA-ORD
BZN-MDW
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
BZN-STL
BIL-ORD
BZN-ORD
FCA-ORD
How far ahead should I book a flight from Montana to Illinois?
Booking 89 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.
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 $118). Flying from Montana to Illinois in May is currently the most expensive (average of $248). 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 May 1, 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 May 1, 2026.
The most flights from USMT to USIL are scheduled on a Thursday (7 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (4 on average).
How much does it cost to fly round-trip from Montana to Illinois?
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 May 1, 2026.
Get a feel of what it's like to fly with Alaska Airlines,Delta, andUnited Airlines 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
Food
7.1
Boarding
8.1
Crew
8.5
Comfort
7.8
Overall
7.9
Reviews
1 / 20
8.0
ExcellentEugene,Mar 2026
MFR - SEA
Entertainment
7.0
Food
7.1
Boarding
8.1
Crew
8.5
Comfort
7.8
Overall
7.9
Reviews
1 / 20
8.0
ExcellentEugene,Mar 2026
MFR - SEA
Entertainment
7.0
Food
7.1
Boarding
8.1
Crew
8.5
Comfort
7.8
Overall
7.9
Reviews
1 / 20
8.0
ExcellentEugene,Mar 2026
MFR - SEA
Entertainment
7.0
Food
7.1
Boarding
8.1
Crew
8.5
Comfort
7.8
Overall
7.9
Reviews
1 / 20
8.0
ExcellentEugene,Mar 2026
MFR - SEA
Entertainment
7.0
Food
7.1
Boarding
8.1
Crew
8.5
Comfort
7.8
Overall
7.9
Reviews
1 / 20
8.0
ExcellentEugene,Mar 2026
MFR - SEA
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 May 1, 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 May 1, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$191 | Average$338 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$229 | Average$437 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$230 | Average$483 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$350 | Average$467 | FlexibilityNo cancel fee | On-time75% |