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 | $138 (American Airlines) |
One-way from | $49 (United Airlines) |
Popular in | July |
Cheapest in | September |
Average price | $290 |
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 12/30
8:05 am-9:40 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
Sat 1/17
6:10 am-11:47 am
1 stop5h 37m
Chicago O'Hare Intl
Sun 1/18
5:30 am-11:05 am
1 stop5h 35m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Sat 1/17
8:05 am-9:40 am
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 12/18
6:05 am-12:40 pm
1 stop6h 35m
Chicago O'Hare Intl
Wed 12/31
12:10 pm-1:36 pm
Nonstop1h 26m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 12/18
8:01 pm-9:30 pm
Nonstop1h 29m
Chicago O'Hare Intl
Tue 1/6
4:45 pm-6:16 pm
Nonstop1h 31m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 1/8
6:00 am-10:59 am
1 stop4h 59m
Chicago O'Hare Intl
Mon 1/12
5:59 pm-11:39 pm
1 stop5h 40m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 12/31
6:30 am-8:05 am
Nonstop1h 35m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Sat 2/14
8:21 am-9:54 am
Nonstop1h 33m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Tue 2/17
7:41 am-9:10 am
Nonstop1h 29m
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 2/18
11:25 am-12:58 pm
Nonstop1h 33m
| 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
Entertainment
Comfort
Crew
Overall
Food
Reviews
Anonymous,Oct 2025
YUL - ORD
Boarding
Entertainment
Comfort
Crew
Overall
Food
Reviews
Anonymous,Oct 2025
YUL - ORD
Boarding
Entertainment
Comfort
Crew
Overall
Food
Reviews
Anonymous,Oct 2025
YUL - ORD
Boarding
Entertainment
Comfort
Crew
Overall
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 |