Cheap flights from San Francisco to St. Louis from $185

In general, April is the cheapest month to fly from San Francisco to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $488. The month of September is another great option to travel to St. Louis, with average flight prices from San Francisco averaging around $492.

The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $504. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $609. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

Flying to St. Louis from San Francisco at noon is the least expensive time of day to depart. momondo users have found prices as low as $530 when looking at flights departing at noon. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $833 per ticket.

Fly from San Francisco to Lambert-St Louis for the best San Francisco - Lambert-St Louis flight prices

You are more likely to see cheaper flights to St. Louis from San Francisco when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $544 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from San Francisco for as low as $470 on momondo.

There are 4 cabin classes available to choose from on San Francisco to St. Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 6% on your flight if you consider stops on a San Francisco to St. Louis flight.

As of September 2026, prices for San Francisco to St. Louis flights are approximately 12% cheaper when compared to flights at the same time last year.

Alaska Airlines, Delta, and United Airlines are the most popular carriers operating from San Francisco to Lambert-St Louis

Southwest, United Airlines and Frontier are the top three most popular airlines that fly to St. Louis from San Francisco according to our data. Southwest is the first choice among our users, with 42% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 6 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

Phoenix (PHX) was the most common stop: 33% of momondo users choosing 1-stop flights on this route connected there.

Flights via Las Vegas (LAS) offer the lowest average round-trip price of $240.

Flights connecting via Phoenix (PHX) have the shortest average one-way travel time: 5h 50m.

Phoenix (PHX) has the shortest average layover time for this route: 0h 49m.

The number of flights available between San Francisco and St. Louis is 2 per day as of September 2026. The most frequent departure time is 12:00PM, with 55% of daily flights leaving in the afternoon.

As of September 2026, 15 flights take off from San Francisco and land in St. Louis each week. The most common flight departure day for this route is Sun, with 27% of weekly flights taking off on this day.