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$124 Cheap Flights from St. Louis (STL) to San Diego (SAN)

View $124 flight on Tue, Oct 6, 2026Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to San Diego Intl. Airport (SAN)

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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 $124 for one-way flights and $240 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Wed, Dec 2 - Sat, Dec 5
STL
St. Louis
SAN
San Diego
$240 Roundtrip, found 2 days ago
$240
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Wed, Dec 2 from St. Louis to San Diego, returning Sat, Dec 5, priced at $240 found 2 days ago
Frontier Airlines
Sat, Oct 10 - Thu, Oct 15
STL
St. Louis
SAN
San Diego
$245 Roundtrip, found 3 days ago
$245
Roundtrip
found 3 days ago
Select Frontier Airlines flight, departing Sat, Oct 10 from St. Louis to San Diego, returning Thu, Oct 15, priced at $245 found 3 days ago
Frontier Airlines
Sat, Nov 7 - Mon, Nov 9
STL
St. Louis
SAN
San Diego
$248 Roundtrip, just found
$248
Roundtrip
just found
Select Frontier Airlines flight, departing Sat, Nov 7 from St. Louis to San Diego, returning Mon, Nov 9, priced at $248 just found
Frontier Airlines
Sat, Oct 31 - Mon, Nov 2
STL
St. Louis
SAN
San Diego
$250 Roundtrip, found 3 days ago
$250
Roundtrip
found 3 days ago
Select Frontier Airlines flight, departing Sat, Oct 31 from St. Louis to San Diego, returning Mon, Nov 2, priced at $250 found 3 days ago
Frontier Airlines
Wed, Oct 14 - Fri, Oct 16
STL
St. Louis
SAN
San Diego
$252 Roundtrip, found 2 days ago
$252
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Wed, Oct 14 from St. Louis to San Diego, returning Fri, Oct 16, priced at $252 found 2 days ago
Frontier Airlines
Mon, Nov 9 - Thu, Nov 12
STL
St. Louis
SAN
San Diego
$257 Roundtrip, found 2 days ago
$257
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Mon, Nov 9 from St. Louis to San Diego, returning Thu, Nov 12, priced at $257 found 2 days ago
American Airlines
Thu, Nov 12 - Wed, Nov 18
STL
St. Louis
SAN
San Diego
$278 Roundtrip, just found
$278
Roundtrip
just found
Select American Airlines flight, departing Thu, Nov 12 from St. Louis to San Diego, returning Wed, Nov 18, priced at $278 just found
Southwest Airlines
Sat, Nov 7 - Mon, Nov 9
STL
St. Louis
SAN
San Diego
$282 Roundtrip, just found
$282
Roundtrip
just found
Select Southwest Airlines flight, departing Sat, Nov 7 from St. Louis to San Diego, returning Mon, Nov 9, priced at $282 just found
Delta
Thu, Nov 12 - Wed, Nov 18
STL
St. Louis
SAN
San Diego
$288 Roundtrip, just found
$288
Roundtrip
just found
Select Delta flight, departing Thu, Nov 12 from St. Louis to San Diego, returning Wed, Nov 18, priced at $288 just found
Alaska Airlines
Tue, Oct 6 - Fri, Oct 9
STL
St. Louis
SAN
San Diego
$307 Roundtrip, just found
$307
Roundtrip
just found
Select Alaska Airlines flight, departing Tue, Oct 6 from St. Louis to San Diego, returning Fri, Oct 9, priced at $307 just found

Alternative airports near San Diego

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to McClellan-Palomar CLD. Average driving time to city center is 38 minutes. Flights from $837
CLD
McClellan-Palomar
Average driving time to city center38 min
Flights from $837

Find the cheapest month to fly from St. Louis (STL) to San Diego (SAN)

September is typically the cheapest month to fly

From $136 - $278 per traveler.

What you need to know for your flight from Lambert-St. Louis Intl. to San Diego Intl.

St. Louis (STL) to San Diego (SAN) at a glance

Explore a range of airlines providing San Diego flights from St. Louis (STL) as you plan your journey from Lambert-St. Louis International Airport to San Diego International Airport. Whether you're looking for cheap flights from St. Louis or prefer full-service options, you can easily compare itineraries to suit your budget, schedule, and travel preferences. Discover the vibrant sights and neighborhoods of San Diego while finding the best flight options for your trip from Saint Louis.

  • Fastest flight duration: around 4 hours non-stop
  • Route distance: roughly 1,600 miles (2,570 km)
  • Flights per week: around 25+ flights with multiple daily departures on average
  • Typical fares (one-way): economy tickets often range from $95–$420, depending on seasonality and how far ahead you book

Flights from Lambert-St. Louis International Airport (STL) to San Diego International Airport (SAN)

Here are the top airlines favored by travelers flying from St. Louis to San Diego, based on recent booking trends. These airlines offer both non-stop and one-stop flights, with popular layover options at Denver International Airport (DEN, approximately 1h 15m), Sky Harbor International Airport (PHX, around 1h 15m), and Dallas-Fort Worth International Airport (DFW, about 1h 30m). This variety allows you to tailor your itinerary by balancing cost, total travel time, and cabin class for an optimal travel experience.

  • Southwest Airlines: This budget-friendly airline provides both non-stop and one-stop options, with one-way ticket prices generally between $135 and $505. It represents around 33% of departures for this route, and the average non-stop flight duration is about 4 hours.
  • American Airlines: As a full-service airline that offers one-stop flights, American Airlines has one-way fares typically ranging from $115 to $395. It accounts for nearly 28% of departures on this route, with an in-flight duration of 5 hours and a total travel time of approximately 6 hours and 30 minutes, including layovers.
  • United: Another full-service option, United provides one-stop services with one-way fares often ranging from $120 to $450. It constitutes approximately 13% of departures along this route, featuring an in-flight time of 5 hours and a total journey time of about 6 hours and 30 minutes, including layovers.
  • Frontier Airlines: Known as a low-cost option, Frontier Airlines offers one-stop service with one-way fares typically between $95 and $255. It makes up roughly 12% of departures on this route, with an in-flight duration of 5 hours and a total time of around 6 hours and 30 minutes, factoring in layovers.
  • Delta: Delta operates as a full-service airline providing one-stop flights, with one-way fares usually ranging from $125 to $360. It also accounts for about 12% of departures on this route, with a flight duration of 5 hours and a total travel time of approximately 6 hours and 30 minutes, including layovers.

Travelers flying from St. Louis to San Diego have the option to enhance their experience with an upgrade. United Airlines offers first class, while Delta provides both first class and premium economy service.

Best time to fly from St. Louis (STL) to San Diego (SAN)

The most popular months for travelers flying from St. Louis to San Diego are January, March, and April, when peak temperatures in San Diego reach up to 60.6°F in April. If you prefer quieter travel, consider October, the least busy time to visit with temperatures around 68.2°F and typically the lowest average one-way fare (around $203). Flight availability peaks in June, with approximately 30 flights per week, making it easier to find convenient departure times. January has the fewest flights, with approximately 21 flights per week.

  • Cheapest time to fly: October usually offers good deals with average one-way fare around $203, roughly 10% cheaper than the yearly average.
  • More budget-friendly months to fly: June, April, and January typically offer average one-way fares of around $210.
  • Most flight options: June has the highest number of flights from St. Louis to San Diego, with approximately 30 flights per week, giving you more flexibility in scheduling your trip.
calendar iconMonthtemperature iconTemperaturecrowd level iconDemandflights iconWeekly Flightsprice iconAverage one-way Fare
January57.4°F (14.1°C)Moderately High21$213
February56.8°F (13.8°C)Average22$228
March58.1°F (14.5°C)Moderately High29$239
April60.6°F (15.9°C)Moderately High28$208
May62.6°F (17.0°C)Average29$217
June66.4°F (19.1°C)Average30$207
July70.5°F (21.4°C)Average28$241
August72.3°F (22.4°C)Average26$228
September72.0°F (22.2°C)Moderately Low26$229
October68.2°F (20.1°C)Moderately Low28$203
November62.6°F (17.0°C)Average27$228
December57.4°F (14.1°C)Moderately Low24$266

*Average one-way fare is based on Expedia flight booking data from January 2025 to April 2026 for the specified route and travel class and may change depending on availability, dates, and demand.

Alternative routes from St. Louis (STL) to San Diego (SAN)

  • St. Louis to Carlsbad (STL-CLD): McClellan-Palomar Airport (CLD) is located approximately 28 miles from San Diego International Airport (SAN). One-way economy ticket prices for this journey generally fall between $120 and $420, influenced by the season and how far in advance you book. Flights on this route typically involve one-stop connections, primarily through Sky Harbor International Airport (PHX). American Airlines is the leading carrier for this route, and first-class service is also offered.
  • Springfield to San Diego (SPI-SAN): Abraham Lincoln Capital Airport (SPI) is roughly 85 miles from Lambert-St. Louis International Airport (STL). The one-way economy fares for this route usually range from $200 to $580, depending on the time of year and booking timing. This route commonly features one-stop flights, with most connections occurring at O'Hare International Airport (ORD). American Airlines is the most frequently used airline on this route, and first-class service is available as well.

How to find the best prices for flights from St. Louis (STL) to San Diego (SAN)

Getting some of the best deals on flights from St. Louis to San Diego is all about timing and flexibility. Here are some key tips to help you save:

  1. Best times to book and fly: cheaper fares are usually found when booking 2 to 8 weeks in advance, which coincides with when most travelers make their reservations. Evening departures from 6 PM to 12 AM tend to be less expensive, while morning flights from 5 AM to 12 PM are more popular. Additionally, flying on Wednesday typically offers lower prices, although Friday remains the most favored travel day.
  2. Set up price alerts: stay updated on price changes by using Expedia's Price Tracker. Receive alerts when fares drop for your selected route.
  3. Bundle and save: bundle your flight and hotel to save on Expedia, or unlock a hotel deal after booking your flight.* Find San Diego hotel and flight deals.
  4. Compare flight options: use Expedia's search tool to compare airlines, routes, direct vs. non-direct flights, and flight times. You can also sort by price to find the most affordable options.
  5. Stay flexible with dates: being open to different travel days can sometimes help you find better prices on flights and hotels.
  6. Think about luggage: nowadays, it's important to check the airline's baggage policies to find the best value. That may be paying for an additional carry-on bag or booking a ticket with checked luggage included. Either way, double-check your allowance before confirming your booking to avoid excess baggage fees at the airport.

*Members only. Savings vary and are not available on all bundles. Select hotels.

Arriving at San Diego International Airport from Lambert-St. Louis International Airport

San Diego welcomes travelers from St. Louis with a range of transport options based on price, convenience, and proximity. Here's how to reach San Diego efficiently:

  • Hotel transfer: Transfers offer a convenient way to reach your hotel in San Diego, with options including free hotel shuttles and private rides, which can be arranged in advance with your hotel.
  • Car rental: Renting a car from San Diego International Airport is a great option if you plan to explore and sightsee beyond the city. Browse cheap car rentals at San Diego International Airport on Expedia.
  • Taxi/ride-hailing: Taxis and ride-hailing services may be available from designated pickup areas outside the terminal, check locally on arrival.
  • Public transportation: From San Diego International Airport, the nearby Seaport is just about 0.1 miles away on foot, while Middletown Station, a metro station, is located approximately 2.3 miles from the airport by car. If you're planning to embark on a cruise, the B Street Cruise Ship Terminal is situated around 3 miles away by car, making it easily accessible for travelers.

Frequently asked questions

How much does a flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) cost?
You can find cheap one-way flights from $124 and cheap return flights from $240 St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) with Expedia. One-way flights generally range between $130 and $1061, and roundtrip flights usually range from $346 to $1147. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) ticket fares go up or down.*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
April is the cheapest month to fly from St. Louis, MO (STL) to San Diego, CA (SAN), with average return fares around $350. This fare is about 12% lower than the average price throughout the year, as spring often sees a dip in travel demand. Other budget-friendly months include February and May.*Averages based on flights available on Expedia in the last year.
Which airlines fly direct from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
Enter STL to SAN and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
What is the cheapest airline that flies from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
Sun Country Airlines is one of the cheapest airlines offering connecting flights from STL to SAN, with round-trip tickets starting from around $261. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
To find a cheap flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best airline to fly with from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
The best airline to fly with from St. Louis, MO (STL) to San Diego, CA (SAN) will differ from traveler to traveler. If you like to fly early, WN offers early morning flights. If price is the most important factor, WN typically offers the lowest fares. WN offers the most daily flights from STL to SAN, which is great if flexibility is what you value most. The best carrier for this journey could also be the one you have a loyalty membership with, as flying with that airline or another airline within the same alliance could help you collect points or enjoy lounge access.
What is the best time to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
The best time to fly from St. Louis, MO (STL) to San Diego, CA (SAN) is in April or May, with average return flight prices around $350. These months are ideal as they provide a combination of good weather and lower travel demand, ensuring a more enjoyable trip.*Prices based on flights available on Expedia in the last year.
How many flights per day from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
On average, there are around 1 nonstop flights per day from Lambert-St. Louis Intl. (STL) to San Diego Intl. (SAN). For more options, look at flights that include layovers.
What is the earliest flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
Sort flights by "Departure (earliest)" on Expedia to find the earliest flight from STL to SAN. To compare more early flights, use the "Early Morning" and "Morning" filters in your search.
What are the most popular departure times for flights from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
The most popular departure times for flights from Lambert-St. Louis International Airport (STL) to San Diego International Airport (SAN) are in the early morning, from 6am to 9am. About 27% of passengers prefer this time window. Many major carriers, including American Airlines, Southwest Airlines, and United Airlines, offer flights during this window. This timing works well because it lets you maximize your day in San Diego upon arrival.
How long does it take to fly from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
A nonstop flight from STL to SAN typically takes around 4 hours, covering approximately 1,555 miles. Connecting flights on this route usually add 3 hours 50 minutes to your travel time. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
You can fly first class between STL and SAN. First class cabins are available on:

  • American Airlines
  • United Airlines
  • Delta Air Lines

How do I earn miles on a St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) flight with Expedia?
It's easy to earn miles on a St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for San Diego from Lambert-St. Louis Intl. (STL)?
If you're planning to travel to San Diego from Lambert-St. Louis Intl. (STL), you can fly into San Diego Intl. (SAN) Some flights may connect through major hubs like Seattle - Tacoma Intl. (SEA), Wichita Dwight D. Eisenhower National (ICT), Denver Intl. (DEN) before reaching San Diego. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) at the last minute?
Typically, booking a last minute flight from St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) flight and hotel package?
Securing a St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) San Diego Vacation Packages is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities 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 St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.)?
If you booked your St. Louis, MO (STL-Lambert-St. Louis Intl.) to San Diego, CA (SAN-San Diego Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

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
$240
Distance
1554 mi
Average flight time
3 hours 4 mins

Book with confidence

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 December. 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 2026. You can also book with separate airlines for your outbound and return journeys, from $124 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.

 

St. Louis to San Diego Flights

*Flight schedules are subject to change.

*Available to One Key members.

 

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