$211 Find Cheap Flights from Ottawa to St. Louis - Compare and Save

Flights from Ottawa to St. Louis usually depart from Ottawa (YOW) and arrive at Lambert-St Louis (STL).

Only Economy Class is available on flights from Ottawa to St. Louis.

One-stop flights from Ottawa to St. Louis most commonly connect through:

• Toronto Pearson Intl (YYZ) - 52% of one-stop connections
• Chicago O'Hare Intl (ORD) - 38% of one-stop connections
• Montreal Pierre Elliott Trudeau Intl (YUL) - 6% of one-stop connections
• Newark (EWR) - 4% 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 55% on the Ottawa to St. Louis route. Tuesday is the cheapest departure day at $285 round-trip on average, while Monday is the most expensive at $629, a difference of $344. 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 Downtown St. Louis, Busch Stadium and Enterprise Center. These are among the most viewed places in St. Louis on KAYAK.

A nonstop flight from Ottawa to St. Louis takes 0h 00m, covering 878 miles.

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 $446 to $1,146. That means the highest observed fare was about 3x higher than the lowest one.

One-way fares from Ottawa to St. Louis are currently lower than usual. Average one-way flight prices are about $279, which is 24% below the typical average for this route.

Flying via Toronto Pearson Intl (YYZ) gives the shortest average 1-stop total travel time at 5h 32m, compared with 5h 32m via Montreal Pierre Elliott Trudeau Intl (YUL) and 6h 14m via Chicago O'Hare Intl (ORD).

St. Louis is 1 hour behind Ottawa (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 $31 for economy cars. Top options include:
• Hertz
• Budget
• Alamo
• Enterprise Rent-A-Car
• Payless

Round-trip flights from Ottawa to St. Louis range from $352 to $533, with an average of $464 over the past 12 months. Anything below $352 counts as a good deal.