Cheap Flights from San Diego to St. Louis from $84

Frequently Asked Questions

• What are the cheapest flights from San Diego to St. Louis (SAN-STL)?

  Based on Trip.com data, Frontier Airlines offers one-way fares as low as $84 on Cheapest nonstop routes (e.g. SAN to STL on Thu, Oct 15), while Frontier Airlines offers Cheapest nonstop round-trips from $168 departing on Sun, Sep 13 and returning on Tue, Sep 15.

• Which airlines offer direct flights from San Diego to St. Louis?

  At the moment, you can catch a nonstop flight from San Diego to St. Louis with the following airlines, including: Frontier Airlines Selected airlines are based on historical data collected from flight bookings users made on Trip.com within the last 90 days.

• How long does it take to fly from San Diego (SAN) to St. Louis (STL) and what is the distance?

  It takes around 5 hours 33 minutes to fly from San Diego (SAN) to St. Louis (STL).

• When is the best time to book flights from San Diego to St. Louis?

  By analyzing data from all airlines on the Trip.com flight calendar, it looks like the best time to book a flight from San Diego to St. Louis is around 40 days (6 weeks) in advance, and the best time to fly is usually on Tuesday, Wednesday, and Saturday. Tuesday typically offers the cheapest flights for departure, while Saturday offers the best return deals.

• How many flights are there per week from San Diego to St. Louis?

  Based on Trip.com data in the past 4 weeks, there is 1 flight per week flying from San Diego to St. Louis. You can check the weekly schedule for popular airlines on this route below: American Airlines: -/-/-/-/-/-/- -- AA518 (14:02)

• How can I find the best deals on flights from San Diego to St. Louis?

  To find best deals on flights from San Diego to St. Louis, you can use various tools on Trip.com:
  · Be flexible with your travel dates to get the cheapest flight deal. Now the cheapest flight deal is on Thu, Oct 15, with one-way flights priced at just $84.
  · Compare airlines strategically. Budget carriers often provide the lowest base fares, while we found the most affordable airline currently operating on this route is Frontier Airlines.
  · Set up price alerts to easily monitor ticket prices without having to check every day.
  · Check Trip.com flight deals and promo codes frequently.
  · Avoid peak season unless you book very early. It seems the peak season for St. Louis travel is around July.
  · Get exclusive promo codes for Trip.com app users.

• When are flight tickets from San Diego (SAN) to St. Louis (STL) the cheapest?

  The cheapest months to fly from San Diego to St. Louis is November, when demand for travel is lower.

• Which upcoming date is cheapest to fly from San Diego to St. Louis on?

  After crunching the numbers on our September flight calendar, it's currently cheapest to fly from San Diego to St. Louis on September 12, 2026 with Frontier Airlines, with prices starting at $168.

• Which airports can I fly into St. Louis from San Diego?

  You can arrive at any of the following airports in St. Louis: St. Louis Lambert International Airport (STL), and St. Louis Downtown Airport (CPS). Flights from San Diego International Airport to St. Louis Lambert International Airport (SAN-STL) are by far the most popular option for this route.

• Is there any time difference between San Diego and St. Louis?

  The time difference between St. Louis and San Diego is 2h.

• How do I change or cancel my ticket from San Diego to St. Louis?

  Tickets can only be changed or canceled if permitted by airline policy. To submit a change or cancellation request, go to the flight bookings page, select the option to change or cancel your booking, choose the relevant passengers and segment, and submit a request. Please note that additional charges may apply according to the airline ticket policy. However, if the flight has been rescheduled and you would like to change or cancel your ticket, you can submit an involuntary cancellation request. For more details about change and cancellation policies, please check the customer support pages.

• What is the average cost of a one-way flight from San Diego to St. Louis?

  Based on Trip.com data for flights departing in the next 30 days, the average one-way fare from San Diego to St. Louis is $250. Fares vary by travel date, airline and availability.

• What is the average cost of a round-trip flight from San Diego to St. Louis?

  Based on Trip.com data for travel in the next 30 days, the average round-trip fare from San Diego to St. Louis is $449. The final price depends on the outbound and return dates, airline and fare conditions.

• How do I book flights from San Diego to St. Louis on Trip.com?

  Enter San Diego and St. Louis, choose your travel dates and passengers, then compare flights by price, duration and baggage. Select a fare, review the change and cancellation rules, enter traveler details and complete payment to receive your confirmation.

• Are there budget airlines on the San Diego to St. Louis route?

  Frontier Airlinesare the most popular budget airlines flying from San Diego to St. Louis. Check baggage, seat and payment fees before comparing the final price.