Cheap flights from St. Louis to Ontario from $84
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Ontario departing on 5/5. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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How to get the cheapest flight ticket from St. Louis to Ontario
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the typical price of a round-trip flight between St. Louis and Ontario?
What is the cheapest month to fly to Ontario?
In general, February is the cheapest month to fly from St. Louis to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $213. If you aren’t able to travel during the month of February, then book flights to Ontario from St. Louis during June instead. Flights to Ontario in June, while not as cheap as those in February, still average around $242.
What is the cheapest day to depart on your flight to Ontario?
The cheapest day to depart on your flight to Ontario is on a Tuesday when prices can be found for as low as $291. This is often the case because there is less demand to fly during this day of the week. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from St. Louis to Ontario for around $376.
What is the cheapest time of day to depart on your flight to Ontario?
In the afternoon is the cheapest time of day to fly from St. Louis to Ontario when you can find flight prices for as low as $361. Flying to Ontario in the afternoon is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $442 on average. Flights to Ontario from St. Louis in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.
How far in advance should I book a flight to Ontario?
You are more likely to see cheaper flights to Ontario from St. Louis when booking 10 weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $356 when searching 10 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from St. Louis for as low as $180 on momondo.
What is the cheapest airline that flies from Lambert-St Louis to Ontario?
Frontier, Delta, and Southwest are the most popular carriers operating from Lambert-St Louis to Ontario
What airlines fly to Ontario?
American Airlines, Southwest and Frontier are the top three most popular airlines that fly to Ontario from St. Louis according to our data. American Airlines is the first choice among our users, with 51% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 7 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.
When to book flights from St. Louis to Ontario
Cheap St. Louis to Ontario (STL to ONT) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from St. Louis to Ontario
How far is Lambert-St Louis to Ontario by plane?
A flight from Lambert-St Louis to Ontario will travel around 1552.8 mi. 5h 21m is a normal flight duration for this route.
When did momondo last update prices for flights from Lambert-St Louis Airport to Ontario Airport?
Prices for flights from Lambert-St Louis Airport to Ontario Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Lambert-St Louis Airport to Ontario Airport?
The number of operators available for flights from Lambert-St Louis Airport to Ontario Airport is 5 as of April 2025.
How old do you have to be to fly from Lambert-St Louis Airport to Ontario Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Lambert-St Louis Airport to Ontario Airport.
What documentation or ID do you need to fly to Ontario Airport?
The required travel and health documents for your Ontario Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Ontario Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular plane model from St. Louis to Ontario?
momondo data reveals that the most frequently booked plane model on the route from St. Louis to Ontario is Airbus A320neo, representing 100.00% of all bookings.
What is the most popular airline from St. Louis to Ontario?
momondo data reveals that the most frequently booked airline on the route from St. Louis to Ontario is Frontier, representing 43% of all bookings. The subsequent popular airlines are Southwest at 22%, American Airlines at 20%, and United Airlines at 8%.
Best airlines flying from St. Louis to Ontario
Compare and see reviews for airlines that fly from St. Louis to Ontario with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $128 | Free Cancellation | Rating 5.9 3,283 reviews | |||
| PriceFrom $181 | Free Cancellation | Rating 8.0 7,920 reviews | |||
| PriceFrom $281 | Free Cancellation | Rating 7.2 10,000 reviews | |||
| PriceFrom $326 | Free Cancellation | Rating 7.4 8,685 reviews | |||
| PriceFrom $341 | Free Cancellation | Rating 8.0 4,287 reviews |
Why use momondo?
Why should I use momondo to find a flight deal from St. Louis to Ontario?
Finding the right flight to Ontario from St. Louis is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Ontario quick and easy, saving you time and money.
Can I find flights from St. Louis to Ontario with flexible booking policies on momondo?
Yes. momondo enables you to select and highlight flights to Ontario from St. Louis with this policy.
How can momondo help me find flights from St. Louis to Ontario?
momondo helps you find the best flight between St. Louis and Ontario by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.
I’m not ready to book a flight from St. Louis to Ontario right now. Can momondo alert me if prices change?
If you are simply researching potential flights to Ontario, momondo offers a useful price alert feature which will track prices for flights to Ontario from St. Louis and alert you when they change.