Lufthansa's Economy Flex offers preferred seating and same-day flight changes.
Lufthansa's Free Neighbor Seat allows extra space for a fee on long-haul flights.

Most accurate provider | Mytrip 3 stars |
|---|---|
Most trusted provider | Mytrip 3 stars |
Round-trip from | $130 (Frontier) |
One-way from | $49 (United Airlines) |
Popular in | July |
Cheapest in | September |
Average price | $286 |
Good round-trip deal | $472 or less |
Good one-way deal | $217 or less |
Fly from
Fly to
Route
Depart
Return
Price
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Tue 1/6
12:00 pm-4:44 pm
1 stop4h 44m
Chicago O'Hare Intl
Wed 1/28
5:30 am-11:54 am
1 stop6h 24m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Tue 1/6
12:00 pm-7:35 pm
1 stop7h 35m
Chicago O'Hare Intl
Tue 1/27
8:50 am-2:38 pm
1 stop5h 48m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Fri 12/12
10:42 am-10:24 pm
1 stop11h 42m
Chicago O'Hare Intl
Sun 12/14
7:41 pm-9:52 am
2 stops14h 11m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 1/8
5:11 pm-11:35 am
2 stops18h 24m
Chicago O'Hare Intl
Sun 1/11
8:27 pm-10:33 pm
1 stop26h 06m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 12/31
2:06 pm-3:35 pm
Nonstop1h 29m
Chicago O'Hare Intl
Fri 1/2
10:30 pm-11:55 pm
Nonstop1h 25m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Fri 1/16
11:20 am-12:55 pm
Nonstop1h 35m
Chicago O'Hare Intl
Sun 1/18
1:00 pm-2:30 pm
Nonstop1h 30m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 12/4
12:04 pm-2:57 pm
2 stops26h 53m
Chicago O'Hare Intl
Sun 12/7
9:52 pm-11:22 am
1 stop13h 30m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 12/31
5:13 pm-12:02 am
1 stop6h 49m
Chicago O'Hare Intl
Wed 1/7
11:05 am-4:37 pm
1 stop5h 32m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Tue 12/30
9:55 am-11:30 am
Nonstop1h 35m
Chicago O'Hare Intl
Thu 1/1
4:24 pm-5:54 pm
Nonstop1h 30m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Fri 12/5
3:30 pm-11:08 am
2 stops19h 38m
Chicago O'Hare Intl
Sun 12/7
9:52 pm-11:22 am
1 stop13h 30m
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars |
To ensure you get the cheapest price possible for a flight from St. Louis to Chicago O'Hare Intl Airport, you should look to book at least 75 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.
Currently, September is the cheapest month in which you can book a flight from St. Louis to Chicago O'Hare Intl Airport (average of $93). Flying from St. Louis to Chicago O'Hare Intl Airport in August is currently the most expensive (average of $159). 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.
It’s typically best to fly out from St. Louis to Chicago O'Hare Intl Airport in the morning. Doing so could potentially save you 47% on the flight price compared to flying at noon, which is usually more expensive.
Travelers seeking maximum savings on their St. Louis to Chicago O'Hare Intl Airport flight should consider departing on Thursday mornings when fares are most often at their lowest. Saturday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
Boarding
Overall
Entertainment
Comfort
Crew
Food
Reviews
Anonymous,Oct 2025
YUL - ORD
Boarding
Overall
Entertainment
Comfort
Crew
Food
Reviews
Anonymous,Oct 2025
YUL - ORD
Boarding
Overall
Entertainment
Comfort
Crew
Food
Reviews
Anonymous,Oct 2025
YUL - ORD
Boarding
Overall
Entertainment
Comfort
Crew
Food
Reviews
Anonymous,Oct 2025
YUL - ORD
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$112 | Average$282 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$115 | Average$311 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$140 | Average$221 | FlexibilityNo cancel fee | On-timeN/A |