Cheap Flights from St Louis MO to San Diego International CA from $209

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Flight deals from St Louis to San Diego International

Looking for a cheap last-minute deal or the best round-trip flight from St Louis Airport to San Diego International Airport? If you want to travel next month, round-trip fares start from $223. Find the lowest prices on one-way and round-trip tickets right here.

San Diego.$209 per passenger.Departing Wed, Jul 1, returning Wed, Jul 8.Round-trip flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from St Louis on Wed, Jul 1, arriving in San Diego International.Inbound indirect flight with Frontier Airlines, departing from San Diego International on Wed, Jul 8, arriving in St Louis.Price includes taxes and charges.From $209, select.

San Diego.$210 per passenger.Departing Tue, Jul 28, returning Wed, Aug 5.Round-trip flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from St Louis on Tue, Jul 28, arriving in San Diego International.Inbound indirect flight with Frontier Airlines, departing from San Diego International on Wed, Aug 5, arriving in St Louis.Price includes taxes and charges.From $210, select.

San Diego.$210 per passenger.Departing Tue, Aug 11, returning Wed, Aug 19.Round-trip flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from St Louis on Tue, Aug 11, arriving in San Diego International.Inbound indirect flight with Frontier Airlines, departing from San Diego International on Wed, Aug 19, arriving in St Louis.Price includes taxes and charges.From $210, select.

San Diego.$223 per passenger.Departing Sat, Jun 6, returning Wed, Jun 17.Round-trip flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from St Louis on Sat, Jun 6, arriving in San Diego International.Inbound indirect flight with Frontier Airlines, departing from San Diego International on Wed, Jun 17, arriving in St Louis.Price includes taxes and charges.From $223, select.

San Diego.$230 per passenger.Departing Mon, May 25, returning Wed, Jun 3.Round-trip flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from St Louis on Mon, May 25, arriving in San Diego International.Inbound indirect flight with Frontier Airlines, departing from San Diego International on Wed, Jun 3, arriving in St Louis.Price includes taxes and charges.From $230, select.

San Diego.$243 per passenger.Departing Sat, Jun 27, returning Sat, Jul 4.Round-trip flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from St Louis on Sat, Jun 27, arriving in San Diego International.Inbound indirect flight with Frontier Airlines, departing from San Diego International on Sat, Jul 4, arriving in St Louis.Price includes taxes and charges.From $243, select.

San Diego.$249 per passenger.Departing Tue, May 26, returning Sun, May 31.Round-trip flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from St Louis on Tue, May 26, arriving in San Diego International.Inbound indirect flight with Frontier Airlines, departing from San Diego International on Sun, May 31, arriving in St Louis.Price includes taxes and charges.From $249, select.

San Diego.$250 per passenger.Departing Fri, Sep 4, returning Mon, Sep 7.Round-trip flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from St Louis on Fri, Sep 4, arriving in San Diego International.Inbound indirect flight with Frontier Airlines, departing from San Diego International on Mon, Sep 7, arriving in St Louis.Price includes taxes and charges.From $250, select.

San Diego.$291 per passenger.Departing Sat, Aug 29, returning Sat, Sep 12.Round-trip flight with United.Outbound indirect flight with United, departing from St Louis on Sat, Aug 29, arriving in San Diego International.Inbound indirect flight with United, departing from San Diego International on Sat, Sep 12, arriving in St Louis.Price includes taxes and charges.From $291, select.

San Diego.$295 per passenger.Departing Thu, Sep 24, returning Thu, Oct 1.Round-trip flight with United.Outbound indirect flight with United, departing from St Louis on Thu, Sep 24, arriving in San Diego International.Inbound indirect flight with United, departing from San Diego International on Thu, Oct 1, arriving in St Louis.Price includes taxes and charges.From $295, select.

San Diego.$295 per passenger.Departing Tue, Oct 6, returning Fri, Oct 9.Round-trip flight with Delta.Outbound indirect flight with Delta, departing from St Louis on Tue, Oct 6, arriving in San Diego International.Inbound indirect flight with Delta, departing from San Diego International on Fri, Oct 9, arriving in St Louis.Price includes taxes and charges.From $295, select.

San Diego.$297 per passenger.Departing Sun, Nov 22, returning Fri, Nov 27.Round-trip flight with United.Outbound indirect flight with United, departing from St Louis on Sun, Nov 22, arriving in San Diego International.Inbound indirect flight with United, departing from San Diego International on Fri, Nov 27, arriving in St Louis.Price includes taxes and charges.From $297, select.

San Diego.$398 per passenger.Departing Sat, Oct 31, returning Sun, Nov 8.Round-trip flight with Delta.Outbound indirect flight with Delta, departing from St Louis on Sat, Oct 31, arriving in San Diego International.Inbound indirect flight with Delta, departing from San Diego International on Sun, Nov 8, arriving in St Louis.Price includes taxes and charges.From $398, select.

San Diego.$1,137 per passenger.Departing Wed, May 13, returning Mon, May 18.Round-trip flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departing from St Louis on Wed, May 13, arriving in San Diego International.Inbound direct flight with Southwest Airlines departing from San Diego International on Mon, May 18, arriving in St Louis.Price includes taxes and charges.From $1,137, select.

Find the cheapest month to fly from St Louis to San Diego International

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

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Direct flights from St Louis to San Diego International

St Louis to San Diego International: Alternative routes

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

San Diego International

4km from central San Diego

ClosestCheapest

from $209

Search flights

McClellan – Palomar

48km from central San Diego

from $465

Search flights

St Louis to San Diego: Flight information

The things to know before you go.

Cheapest flight found	$209
Cheapest month to fly	July
Average flight time	3 hrs, 51 mins
Most popular airline	Southwest Airlines
Average flights per week	7

Finding cheap flights from St Louis to San Diego International: Frequently asked questions

How much are round-trip flights from St Louis to San Diego International?

The best price we found for a round-trip flight from St Louis to San Diego International is $209. 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.

How long does it take to fly from St Louis to San Diego International?

3 hours and 51 minutes is the average flight time from St Louis to San Diego International.

Which airlines fly direct from St Louis to San Diego International?

Southwest Airlines flies direct from St Louis to San Diego International.

How many flights are there a week from St Louis to San Diego International?

There are 7 flights per week flying from St Louis to San Diego International, as of May 2026.

When is the cheapest time to fly from St Louis to San Diego International?

The cheapest month to fly from St Louis to San Diego International is usually July.

Which upcoming date is cheapest to fly from St Louis Airport to San Diego International Airport on?

After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from St Louis Airport to San Diego International Airport on Wednesday, July 1, 2026.

Can I get a direct flight from St Louis Airport to San Diego International Airport?

Yes – the average flight time is 3 hours and 51 minutes.

How can I find the best flight deal to San Diego International?

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 San Diego International 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.

When is the best time to book flights to San Diego?

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

Which is the cheapest airline to fly with from St Louis Airport to San Diego International?

Currently, Frontier Airlines and Southwest Airlines offer the cheapest flight tickets to San Diego International.

Flying from Lambert-St. Louis International Airport (STL) to San Diego International Airport (SAN): what you need to know

The average length of a direct flight from Lambert-St. Louis International Airport to San Diego International Airport is 3 hours 55 minutes.
San Diego is two hours behind St Louis and is in the UTC-7 timezone.
Choose from nine weekly Lambert-St. Louis International Airport to San Diego International Airport flights. The 06:15 departure with Southwest Airlines is the earliest you can take. Southwest Airlines operates the latest service of the day at 20:55.
Leave enough time to catch your STL to SAN flight. Generally, it's best to arrive at least two hours before international departures and an hour ahead for domestic flights.
Traveling during a peak month such as July? Major public holidays and other high seasons can lead to longer queues at airport checkpoints. Play things extra safe and arrive up to four hours before an international flight and two hours before a domestic departure.
Jetting into San Diego (and then discovering more of United States!) is a breeze with Southwest Airlines. This popular airline has direct flights from Lambert-St. Louis International Airport to San Diego International Airport.
Southwest Airlines has the highest passenger demand on this route.
The most punctual carrier that operates STL to SAN flights is Southwest Airlines. Its services land as scheduled 72.22% of the time.
If you want to include a stop along the way, simply deselect 'Direct flights only' when searching for your ticket from Lambert-St. Louis International Airport to San Diego International Airport. Here are the top stopovers between STL and SAN:
- Phoenix Sky Harbor International Airport
- Denver International Airport
- Harry Reid Airport (formerly McCarran Airport)

How to find the cheapest flights from Lambert-St. Louis International Airport (STL) to San Diego International Airport (SAN)

Right now, $105 is the lowest price we've seen for a one-way Lambert-St. Louis International Airport to San Diego International Airport flight. The best price for a return ticket is $209. Bear in mind that fares may change due to demand when booking.
To secure cheap tickets from STL to SAN, book your journey seven months ahead of your departure.
June is the cheapest month for flights from Lambert-St. Louis International Airport to San Diego International Airport. If you're looking to travel at a different time of year, the 'Whole month' tool will give you the lowest prices for each month.
You don't need to check back in every day to find out if fares have dropped when you set up a Price Alert. We'll update you the moment there's a better deal on cheap flights from STL to SAN.
Discover the perfect flight for you by using the filters. To see the 'Best,' 'Fastest' or 'Cheapest' flights from Lambert-St. Louis International Airport to San Diego International Airport, use the 'Sort by' tool. You can also filter results by airline, arrival and departure times, and number of stops.

Handy information about Lambert-St. Louis International Airport (STL)

STL's address is 10701 Lambert International Blvd..
Of the departures from Lambert-St. Louis International Airport, 78.04% land on time at their destination.
To get to Lambert-St. Louis International Airport from central St Louis, it takes about 20 minutes by car. Of course, this depends on traffic conditions. It's approximately 26 kilometers from the airport to the city center.
The trip on public transport usually takes 35 minutes.
Searching for a handy hotel close to STL? If you're boarding an early flight from Lambert-St. Louis International Airport to San Diego International Airport, these accommodation options will have you sleeping moments from your departure gate:

Arriving at San Diego International Airport (SAN)

Consider staying in a hotel close to SAN if you have a late Lambert-St. Louis International Airport to San Diego International Airport flight. Settle into one of these accommodation options and skip the long transfer:
Pick up a San Diego International Airport rental car and discover San Diego and beyond with your own set of wheels. Thrifty, Dollar and Budget are leading providers to choose from here.
Secure the lowest price by reserving your vehicle from San Diego International Airport around two weeks before your travel date.

Getting from San Diego International Airport (SAN) to central San Diego

SAN is located at Airport Drive.
San Diego International Airport is approximately 5 kilometers from central San Diego. Driving there takes about 10 minutes.
Traveling on public transport will take you around 20 minutes.

When to fly to San Diego International Airport (SAN)

The quietest month for a flight from Lambert-St. Louis International Airport to San Diego International Airport is May, while July is the busiest. Pick the best time to visit San Diego based on whether you prefer a faster pace or a more relaxed vibe.
When booking your flight from Lambert-St. Louis International Airport to San Diego International Airport, consider the kind of weather you enjoy. August is the warmest month in San Diego, with the temperature ranging from 17ºC (63ºF) to 28ºC (82ºF).
February sees average temperatures of between 7ºC (45ºF) and 23ºC (73ºF). Look for cheap tickets from STL to SAN sometime then if you want to travel when it's cooler.

Explore more of United States

San Diego has plenty going for it, but there are so many other parts of United States waiting to be explored. About 177 kilometers north-west of San Diego, a trip to Los Angeles will keep your itinerary busy. Check out popular attractions like Griffith Observatory, The Broad and La Brea Tar Pits & Museum.
Phoenix is another must-experience destination in United States and is around 483 kilometers east of San Diego. No trip is complete without dropping by Desert Botanical Garden, Heard Museum and Papago Park.