$94 Cheap Flights from St. Louis (STL) to San Diego (SAN)

View $94 flight on Fri, May 9, 2025Opens in a new window

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Cheap Flights from St. Louis to San Diego (STL-SAN)

Prices were available within the past 7 days and start at $94 for one-way flights and $188 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Fri, May 9 - Fri, May 16
STL
St. Louis
SAN
San Diego
$188 Roundtrip, found 10 hours ago
$188
Roundtrip
found 10 hours ago
Select Frontier Airlines flight, departing Fri, May 9 from St. Louis to San Diego, returning Fri, May 16, priced at $188 found 10 hours ago
American Airlines
Sat, May 24 - Wed, May 28
STL
St. Louis
CLD
Carlsbad
$199 Roundtrip, found 1 day ago
$199
Roundtrip
found 1 day ago
Select American Airlines flight, departing Sat, May 24 from St. Louis to Carlsbad, returning Wed, May 28, priced at $199 found 1 day ago
Frontier Airlines
Fri, May 9 - Fri, May 30
STL
St. Louis
SAN
San Diego
$208 Roundtrip, found 3 hours ago
$208
Roundtrip
found 3 hours ago
Select Frontier Airlines flight, departing Fri, May 9 from St. Louis to San Diego, returning Fri, May 30, priced at $208 found 3 hours ago
Frontier Airlines
Sat, May 31 - Sun, Jun 1
STL
St. Louis
SAN
San Diego
$218 Roundtrip, found 11 hours ago
$218
Roundtrip
found 11 hours ago
Select Frontier Airlines flight, departing Sat, May 31 from St. Louis to San Diego, returning Sun, Jun 1, priced at $218 found 11 hours ago
Frontier Airlines
Fri, May 9 - Fri, May 30
STL
St. Louis
SAN
San Diego
$223 Roundtrip, found 3 hours ago
$223
Roundtrip
found 3 hours ago
Select Frontier Airlines flight, departing Fri, May 9 from St. Louis to San Diego, returning Fri, May 30, priced at $223 found 3 hours ago
Frontier Airlines
Fri, May 16 - Mon, May 19
STL
St. Louis
SAN
San Diego
$228 Roundtrip, found 2 hours ago
$228
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Fri, May 16 from St. Louis to San Diego, returning Mon, May 19, priced at $228 found 2 hours ago
Frontier Airlines
Sat, Jun 7 - Mon, Jun 16
STL
St. Louis
SAN
San Diego
$233 Roundtrip, found 1 hour ago
$233
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Sat, Jun 7 from St. Louis to San Diego, returning Mon, Jun 16, priced at $233 found 1 hour ago
American Airlines
Sat, May 24 - Wed, May 28
STL
St. Louis
CLD
Carlsbad
$233 Roundtrip, found 4 days ago
$233
Roundtrip
found 4 days ago
Select American Airlines flight, departing Sat, May 24 from St. Louis to Carlsbad, returning Wed, May 28, priced at $233 found 4 days ago
Frontier Airlines
Wed, May 14 - Wed, May 21
STL
St. Louis
SAN
San Diego
$238 Roundtrip, found 8 hours ago
$238
Roundtrip
found 8 hours ago
Select Frontier Airlines flight, departing Wed, May 14 from St. Louis to San Diego, returning Wed, May 21, priced at $238 found 8 hours ago
Frontier Airlines
Sat, May 24 - Wed, May 28
STL
St. Louis
SAN
San Diego
$242 Roundtrip, found 2 hours ago
$242
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Sat, May 24 from St. Louis to San Diego, returning Wed, May 28, priced at $242 found 2 hours ago
Flights from St. Louis (STL) to San Diego (SAN)
Origin airport
Lambert-St. Louis Intl.
Destination airport
San Diego Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Roundtrip price
$188
Distance
1554 mi

St. Louis to San Diego Flights

The cheapest times to fly from St. Louis to San Diego

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to San Diego are during the month of May. You can find some of the cheapest flights from St. Louis to San Diego with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from St. Louis to San Diego

Sunday is one of the best days to book for cheap flights from St. Louis to San Diego: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from St. Louis to San Diego

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to San Diego in 2025. You can also book with separate airlines for your outbound and return journeys, from $94 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to San Diego flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to San Diego airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN) cost?
Cheap round-trip fares from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN) start from $315. This information is based on the cheapest price found on Expedia for this return journey departing within the next three months. This airfare is for a Southwest Airlines flight leaving STL on May 21 2025 and touching down at SAN. The price was last updated on April 29 2025 and has not changed since.
What is the cheapest month to fly from STL to SAN?
Fly direct from STL to SAN in November to take advantage of cheaper fares. You can find a one-way Southwest Airlines flight for $141 leaving on November 12 2025. This price is based on the cheapest direct flight found on Expedia for this route in the next 330 days. The price was last updated on April 29 2025 and remains unchanged.
Which airlines fly direct from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN)?
Hop on a nonstop flight with Southwest Airlines and journey straight from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN).
What is the cheapest airline that flies from STL to SAN?
Right now, the cheapest carrier offering one-way flights from STL to SAN is Southwest Airlines. You can book a seat on this route from $141. This fare is based on the lowest price found on Expedia departing within the next three months. The flight takes off from STL on July 5 2025. Prices were last updated on April 29 2025 and have not changed since.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN)?
On average, only 1 direct flight departs each day from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN). Looking for more options? Use Expedia’s filter tool to find flights with layovers and add an extra destination to your journey.
What are the most popular departure times for flights from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN)?
The 11 AM departures from STL to SAN are the top choice for many travelers. They can also be more expensive. If you want to save on your fare, book during off-peak hours.
What day of the week has the most flights from STL to SAN?
Friday offers the most flights from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN). Consider leaving on this day and you’ll have a greater chance of finding a departure that fits your plans.
What is the earliest flight from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN)?
Hop on the earliest flight at around 10:20AM UTC-6, departing from Lambert-St. Louis Intl. Airport (STL). You’ll be flying for approximately 4h 10m, coming in to land at San Diego Intl. Airport (SAN) at approximately 12:30PM UTC-8.
How long does it take to fly from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN)?
Flights from STL to SAN have an average travel time of 4 hours and 10 minutes. The total distance between the two airports is 1,550 mi.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN)?
To touch down at San Diego Intl. Airport (SAN) on schedule, select a flight that leaves Lambert-St. Louis Intl. Airport (STL) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this time.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.
What airports do you fly into for San Diego from Lambert-St. Louis Intl. Airport (STL)?
San Diego Intl. Airport (SAN) is the only airport in San Diego with direct flights from Lambert-St. Louis Intl. Airport (STL). Consider the options and find cheap fares on Expedia.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN) last-minute?
Last-minute fares from STL to SAN are typically more expensive. For the lowest prices, start looking for flights well in advance. That being said, if you’re flexible with your travel plans, it’s possible to land a cheap ticket just before your departure.
Is it cheaper to book a STL to SAN flight and hotel package?
Securing a STL to SAN flight and hotel package is typically cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your trip in one place. Select from our wide range of accommodations and then add activities, flights and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to San Diego Intl. Airport (SAN)?
If you booked your STL to SAN flight within the last 24 hours, you may be able to modify or cancel it without fees. Depending on the airline and the ticket type you purchased, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, visit our Customer Service portal for more details.

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