C$ 361 Find Cheap Flights from Montreal to St. Louis – Compare and Save

Among airlines operating Montreal Pierre Elliott Trudeau Intl Airport to St. Louis flights:

• Air Canada: offers extra legroom; offers free seat selection
• United Airlines: offers free seat selection

Extra legroom and free seat selection availability depends on fare class and route.

Only Air Canada operates flights between Montreal Pierre Elliott Trudeau Intl Airport and St. Louis.

Flights from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis usually depart from Montreal Pierre Elliott Trudeau Intl (YUL) and arrive at Lambert-St Louis (STL).

Here are some options for this route, based on selected ticket types and cabin classes:

• Air Canada: a carry-on bag and a checked bag in Economy Class
• United Airlines: a carry-on bag and a checked bag in Economy Class

Bag allowance can vary by ticket type, cabin class, route, and airline, so travellers should check the fare details before booking.

Only Economy Class is available on flights from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis.

On this route, layover flights are cheaper than direct options on average. Layover fares average C$ 480 round-trip via Philadelphia (PHL), compared to C$ 928 for direct.

There is no standard. Checked bag policies vary by airline on this route. Most carriers charge C$ 34–C$ 125 for the first checked bag in economy. Premium fares and elite status bookings typically include a free checked bag.

The Canadair (Bombardier) Regional Jet 900 family is used most often on this route, operated mainly by Air Canada and United Airlines. Other aircraft seen on the route include Embraer 175 variants.

One-stop flights from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis most commonly connect through:

• Toronto Pearson Intl (YYZ) – 59% of one-stop connections
• Chicago O'Hare Intl (ORD) – 21% of one-stop connections
• Detroit Metropolitan Wayne County (DTW) – 12% of one-stop connections
• Newark (EWR) – 2% of one-stop connections

Toronto Pearson Intl (YYZ) handles the largest share of one-stop connections on this route.

Yes. Being flexible with your travel dates can save you up to 23% on the Montreal Pierre Elliott Trudeau Intl Airport to St. Louis route. Thursday is the cheapest departure day at C$ 737 round-trip on average, while Monday is the most expensive at C$ 954, a difference of C$ 218. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

Some of the most popular sights in St. Louis are Forest Park Hotel, Hyatt Regency St Louis At The Arch, and America's Center Convention Complex. These are among the most viewed places in St. Louis on KAYAK.

These are the earliest and latest flight times available from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis:

• Earliest: departs at 4:55 pm and lands at 7:41 pm
• Latest: departs at 4:55 pm and lands at 7:41 pm.

The flight takes about 2h 46m.

A direct flight from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis takes 2h 46m, covering 2,504 km.

Yes, a valid passport is required for this international route. Many destinations require at least six months of validity beyond your travel dates. Check your passport expiry well before booking.

Yes. Based on fares seen in the past 5 days, round-trip prices on this route showed a wide range, from about C$ 585 to C$ 1,557. That means the highest observed fare was about 3x higher than the lowest one.

One-way fares from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis are currently lower than usual. Average one-way flight prices are about C$ 383, which is 25% below the typical average for this route.

Flying via Detroit Metropolitan Wayne County (DTW) gives the shortest average 1-stop total travel time at 5h 02m, compared with 5h 08m via Philadelphia (PHL) and 5h 13m via Toronto Pearson Intl (YYZ).

St. Louis is 1 hour behind Montreal Pierre Elliott Trudeau Intl Airport (Central Time vs Eastern Time). Plan for the time shift when scheduling connections or first-day activities.

Lambert-St Louis Airport (STL) hosts 5 major car rental companies, with daily rates starting from around C$ 42 for economy cars. Top options include:
• Hertz
• Budget
• Alamo
• Enterprise Rent-A-Car
• Payless

Round-trip flights from Montreal Pierre Elliott Trudeau Intl Airport to St. Louis range from C$ 680 to C$ 1,016, with an average of C$ 815 over the past 12 months. Anything below C$ 680 counts as a good deal.

Air Canada is the only airline on the Montreal Pierre Elliott Trudeau Intl Airport to St. Louis route offering in-flight Wi-Fi. Pricing depends on fare class.