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 | eDreams 3 stars |
|---|---|
Most trusted provider | eDreams 3 stars |
Round-trip from | $134 (Kiwi.com) |
One-way from | $68 (Kiwi.com) |
Popular in | July |
Cheapest in | September |
Average price | $345 |
Good round-trip deal | $466 or less |
Good one-way deal | $234 or less |
Fly from
Fly to
Route
Depart
Return
Price
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 2/4
3:46 pm-6:31 pm
1 stop26h 45m
Chicago O'Hare Intl
Wed 2/11
6:02 pm-11:59 pm
2 stops29h 57m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 2/4
10:10 am-11:45 am
Nonstop1h 35m
Chicago O'Hare Intl
Wed 2/11
9:25 pm-10:58 pm
Nonstop1h 33m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 2/18
6:25 am-7:58 am
Nonstop1h 33m
Chicago O'Hare Intl
Wed 2/25
8:10 pm-9:40 pm
Nonstop1h 30m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 3/12
7:41 am-9:10 am
Nonstop1h 29m
Chicago O'Hare Intl
Tue 3/17
9:33 pm-10:59 pm
Nonstop1h 26m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Mon 2/2
8:05 am-9:40 am
Nonstop1h 35m
Chicago O'Hare Intl
Wed 2/4
1:00 pm-2:30 pm
Nonstop1h 30m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 3/11
8:12 pm-9:43 am
1 stop13h 31m
Chicago O'Hare Intl
Sun 3/15
10:53 am-9:49 am
1 stop22h 56m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Tue 2/10
10:19 am-4:57 pm
1 stop6h 38m
Chicago O'Hare Intl
Wed 2/11
5:30 am-11:54 am
1 stop6h 24m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 2/5
8:20 am-12:15 pm
1 stop3h 55m
Chicago O'Hare Intl
Thu 2/12
5:15 pm-11:30 pm
1 stop6h 15m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Tue 3/10
6:29 am-1:17 pm
2 stops6h 48m
Chicago O'Hare Intl
Thu 3/12
6:00 am-11:48 am
1 stop5h 48m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 2/5
11:23 am-9:05 pm
2 stops9h 42m
Chicago O'Hare Intl
Thu 2/12
5:25 am-11:02 am
1 stop5h 37m
| 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 |
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 June is currently the most expensive (average of $171). 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 Friday 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.
Overall
Food
Boarding
Comfort
Crew
Entertainment
Reviews
Anonymous,Oct 2025
YUL - ORD
Overall
Food
Boarding
Comfort
Crew
Entertainment
Reviews
Anonymous,Oct 2025
YUL - ORD
Overall
Food
Boarding
Comfort
Crew
Entertainment
Reviews
Anonymous,Oct 2025
YUL - ORD
Overall
Food
Boarding
Comfort
Crew
Entertainment
Reviews
Anonymous,Oct 2025
YUL - ORD
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$105 | Average$281 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$115 | Average$307 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$140 | Average$219 | FlexibilityNo cancel fee | On-timeN/A |