$130 Find Cheap Flights from Ontario to St. Louis - Compare and Save

In the last 5 days, the lowest price for a flight from Ontario to St. Louis was $87 for a one-way ticket and $174 for a round-trip.

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We unfortunately don’t have that data for this specific route.

SkyTeam, Star Alliance, and oneworld are the airline alliances operating flights between Ontario and St. Louis, with SkyTeam being the most commonly used for this route.

The two airlines most popular with KAYAK users for flights from Ontario to St. Louis are Southwest and Delta. With an average price for the route of $518 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $420 and an overall rating of 7.8.

KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ontario to St. Louis.

KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Ontario is likely to change within 7 days, so travelers know whether to wait or book now.

Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Louis with an airline and back to Ontario with another airline. Booking your flights between Ontario and STL can sometimes prove cheaper using this method.

Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Louis from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.