$528 Cheap Flights from St. Louis (STL) to Santander (SDR)

View $528 flight on Thu, Oct 2, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Santander (SDR)

  • Plan, book, fly with confidence

  • trending down icon

    Be in the know

    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon

    Book smarter

    Save up to 30% on select hotels after you book a flight*
  • one key icon

    Earn twice

    Earn your airline miles on top of our OneKeyCash
    Learn about One Key

Cheap Flights from St. Louis to Santander (STL-SDR)

Prices were available within the past 7 days and start at $528 for one-way flights and $697 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Iberia
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$697 Roundtrip, found 5 days ago
$697
Roundtrip
found 5 days ago
Select Iberia flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $697 found 5 days ago
British Airways
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$700 Roundtrip, found 5 days ago
$700
Roundtrip
found 5 days ago
Select British Airways flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $700 found 5 days ago
Iberia
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$730 Roundtrip, found 5 days ago
$730
Roundtrip
found 5 days ago
Select Iberia flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $730 found 5 days ago
Iberia
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$735 Roundtrip, found 5 days ago
$735
Roundtrip
found 5 days ago
Select Iberia flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $735 found 5 days ago
Iberia
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$738 Roundtrip, found 5 days ago
$738
Roundtrip
found 5 days ago
Select Iberia flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $738 found 5 days ago
Iberia
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$767 Roundtrip, found 5 days ago
$767
Roundtrip
found 5 days ago
Select Iberia flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $767 found 5 days ago
American Airlines
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$775 Roundtrip, found 5 days ago
$775
Roundtrip
found 5 days ago
Select American Airlines flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $775 found 5 days ago
Iberia
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$780 Roundtrip, found 5 days ago
$780
Roundtrip
found 5 days ago
Select Iberia flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $780 found 5 days ago
Iberia
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$785 Roundtrip, found 5 days ago
$785
Roundtrip
found 5 days ago
Select Iberia flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $785 found 5 days ago
American Airlines
Thu, Oct 2 - Thu, Oct 9
STL
St. Louis
SDR
Santander
$788 Roundtrip, found 5 days ago
$788
Roundtrip
found 5 days ago
Select American Airlines flight, departing Thu, Oct 2 from St. Louis to Santander, returning Thu, Oct 9, priced at $788 found 5 days ago
Flights from St. Louis (STL) to Santander (SDR)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Santander
Roundtrip price
$697
Distance
4306 mi

St. Louis to Santander Flights

The cheapest times to fly from St. Louis to Santander

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 Santander are during the month of October. You can find some of the cheapest flights from St. Louis to Santander with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from St. Louis to Santander

Sunday is one of the best days to book for cheap flights from St. Louis to Santander: 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 Santander

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 Santander in 2025. You can also book with separate airlines for your outbound and return journeys, from $528 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 Santander 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 Santander 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 Santander Airport (SDR) cost?
Secure a cheap one-way flight from $528 or cheap return flight from $697 from Lambert-St. Louis Intl. Airport (STL) to Santander Airport (SDR) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight deals on this route.
What is the cheapest month to fly from Lambert-St. Louis Intl. Airport (STL) to Santander Airport (SDR)?
October is the cheapest month to fly from STL to SDR. Traveling during an off-peak travel window is often the key to finding a great deal.
What is the cheapest airline that flies from Lambert-St. Louis Intl. Airport (STL) to Santander Airport (SDR)?
To find the cheapest airline flying from STL to SDR, use Expedia's filter tool. Tailor your search based on your travel needs, such as preferred carriers and number of stops. You can then sort your results by "Price (lowest to highest)" to discover the cheapest flight right away.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Santander Airport (SDR)?
You'll have to hop on a flight with a layover if you're traveling from Lambert-St. Louis Intl. Airport (STL) to Santander Airport (SDR). There are no daily direct flights on this route. However, just filter your search to include one or more stops to find the best option for your trip.
What day of the week has the most flights from STL to SDR?
You'll generally find Tuesday the quietest day for flights, while Fridays tend to be the busiest.* However this can vary from season to season and during public holidays or peak travel times.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Santander Airport (SDR)?
To avoid possible delays on the Lambert-St. Louis Intl. Airport (STL) to Santander Airport (SDR) route, travel before 3 PM. Departures after this hour have a 22% higher chance of being canceled.**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.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Santander Airport (SDR) last-minute?
Last-minute fares from STL to SDR are typically more expensive. To lock in the lowest rates, start looking for flights ahead of time. That said, if you can play around with your travel dates, you may land a cheap ticket right before you leave.
Is it cheaper to book a STL to SDR flight and hotel package?
Booking a STL to SDR flight and hotel package is typically cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels in one place. Choose from our extensive range of hotels and then add car rentals, activities and flights 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 Santander Airport (SDR)?
If you reserved your STL to SDR flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the ticket type you purchased, additional charges may apply for changes after that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal for more details.

Explore a world of travel with Expedia

*Available to One Key members.