Cheap flights from St. Louis to San Diego from $80

If you are unable to visit San Diego during the month of September, then departing from St. Louis during the month July is also very affordable. Most momondo users find prices during this month for around $373.

The cheapest day to depart from St. Louis to San Diego is on a Wednesday. Travelers who choose to depart for San Diego on a Wednesday will often find tickets for as low as $442. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $559. These prices are subject to change though, so be sure to set up a Price Alert for flights to San Diego.

The cheapest time of day to fly to San Diego is in the afternoon when flights can be purchased for as low as $422. Flights at noon are often more expensive with an average ticket price of $626.

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

You are more likely to see cheaper flights to San Diego from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to San Diego for around $400 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to San Diego from St. Louis for as low as $337 on momondo.

There is only 1 cabin class available to choose from on St. Louis to San Diego flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

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

Southwest, American Airlines and Frontier are the top three most popular airlines that fly to San Diego from St. Louis according to our data. Southwest is the first choice among our users, with 53% of people opting to fly with this airline when traveling to San Diego. Keep in mind that there are 5 different airlines that fly to San Diego on a routine basis, so you have a few additional options to choose from.

Denver (DEN) was the most common stop: 50% of momondo users choosing 1-stop flights on this route connected there.

Flights via Denver (DEN) offer the lowest average round-trip price of $282.

Flights connecting via Denver (DEN) have the shortest average one-way travel time: 6h 04m.

Salt Lake City (SLC) has the shortest average layover time for this route: 0h 48m.

As of August 2026, 1 flights take off from St. Louis and land in San Diego each day. The most common flight departure time for this route is 8:00AM, with 69% of daily flights taking off at noon.

The number of flights available between St. Louis and San Diego is 13 per week as of August 2026. The most frequent departure day is Mon, with 23% of weekly flights leaving on this day.