Ottawa to St Louis Flights, Fares from ₹ 24,005

Compare Ottawa to St Louis flight deals

Find the cheapest month or even day of the year to fly to St Louis

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Find the cheapest month to fly from Ottawa to St Louis

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Ottawa to St Louis flights are currently cheapest in August.

Ottawa to St Louis: Alternative routes

Compare routes from Ottawa to St Louis below. You may find an airport to fly into that's cheaper, faster, or easier than St Louis.

Ottawa to St Louis: Flight information

The things to know before you go.
Cheapest flight found₹ 24,005
Cheapest month to flyAugust

Finding cheap flights from Ottawa to St Louis: Frequently asked questions

The best price we found for a return flight from Ottawa to St Louis is ₹ 50,081. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
Currently, there are no airlines that fly direct from Ottawa to St Louis. But we found flights with one stop from ₹ 50,081.
As of July 2026, there are no flights flying from Ottawa to St Louis.
The cheapest month to fly from Ottawa to St Louis is usually August.
After crunching the numbers on our flight calendar, we found that it is currently cheapest to fly from Ottawa to St Louis Airport on Thursday, 20 August 2026.
No airlines currently offer direct flights between Ottawa and St Louis Airport. Most routes have one or more stops.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to St Louis but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to St Louis is around 40 days in advance, so don’t leave your flight to the last minute.

The cheapest airline that flies to St Louis is United .

Travelling from Ottawa to St Louis Lambert International Airport (STL): What you need to know

  • St Louis Lambert International Airport is located in St Louis. The city is in the UTC-6 timezone and is one hour behind Ottawa.

  • Give yourself plenty of time to make your flight from Ottawa to STL. As a general rule, arrive at least two hours before international departures and an hour ahead for domestic flights.

  • Head to the airport even earlier during popular months like August. Aim for two hours before domestic departures and four hours ahead of international journeys. After checking in, you can use any extra time to grab something to eat or simply relax.

Airports in Ottawa

Ottawa Macdonald-Cartier International Airport (YOW)

  • Located around 14 kilometres from the centre of Ottawa, YOW can be reached in about 20 minutes by car (depending on traffic). The journey on public transport takes roughly 35 minutes.

  • Catching an early flight from Ottawa to St Louis Lambert International Airport? Avoid rushing to the terminal (and get some extra shut-eye) by picking one of these stays near Ottawa Macdonald-Cartier International Airport:

  • Of the flights that depart from Ottawa Macdonald-Cartier International Airport, 58% arrive on time at their destination.

  • The address for YOW is 50 Airport Road.

About St Louis Lambert International Airport (STL)

Getting from St Louis Lambert International Airport (STL) to central St Louis

  • From St Louis Lambert International Airport, central St Louis is around 24 kilometres away. It takes about 25 minutes to get to the city centre by car.

  • When travelling by public transport, expect a journey time of roughly 30 minutes.

How to find the cheapest flights from Ottawa to St Louis Lambert International Airport (STL)

  • The cheapest price we've found for a one-way ticket from Ottawa to St Louis Lambert International Airport is ₹ 24,005. For a return flight on this route, the best price is ₹ 50,081. Depending on the availability and when you book, these fares may change.

  • Don't leave everything to the last minute. You're more likely to find cheap flights from Ottawa to STL if you book ahead. Airlines often offer some great early bird deals.

  • The 'Whole month' search tool will show you the cheapest Ottawa to St Louis Lambert International Airport tickets throughout the month. It's an easy way to snap up a bargain if your plans aren't set in stone.

  • There's no need to check every day to find out if prices have dropped when you create a Price Alert. We'll notify you when there's a better deal on plane tickets from Ottawa to STL.

  • Lock in a cheap flight from Ottawa to St Louis Lambert International Airport by using filters. Select your ideal times, airlines and number of stops, then sort the results by 'Cheapest' for the best deals.

The best time to fly from Ottawa to St Louis Lambert International Airport (STL)

  • Think about your travel style when planning your trip dates. September is the quietest month to go to St Louis. October is when most people book flights from Ottawa to St Louis Lambert International Airport (STL), which may be ideal if you'd rather travel when it's busy.

  • The warmest month in St Louis is July, with temperatures ranging between 17ºC and 33ºC. Lock in your Ottawa to STL plane ticket then if that's your idea of comfortable weather.

  • January sees temperatures of between -8ºC and 7ºC. Search for cheap tickets from Ottawa to St Louis Lambert International Airport around that time if you want to travel when it's cooler.

More about St Louis

Explore more of the United States

  • You've visited St Louis, now it's time to discover other parts of the United States. Travel around 257 kilometres east to Evansville to tick off its leading attractions. From Mesker Park Zoo to Riverfront Park and Evansville Zoological Society, there's plenty to keep you on the go.

  • Columbia is another essential stop in the United States and is around 177 kilometres west of St Louis. No journey is complete without dropping by Sentinel Park, Bur Oak Brewing Company and Museum of Art and Archaeology.

Prices shown on this page are estimated lowest prices only. Found in the last 12 days.