St Louis to San Juan flights

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Lowest observed

€126

Cheapest month

October 2026

Last checked

10 Oct 2026

Observed fares. Prices may change.

Your next trip, last seen at €126

31 Oct 2026

1 stop · One way

Cheapest observed day · Last checked: 10 Oct 2026

When to fly

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The lowest fare we observed for each month. Open a month to see its days, then pick your outbound and return. A day with no price is one we will search for you.

Prices are for observed departure and return date pairs. No data does not mean no flights.

Lowest observed: €126, departing 31 Oct 2026 (Last checked: 10 Oct 2026)One-way fareCheck live prices for this route
Airlines seen: Frontier Airlines, Southern Airways Express, United Airlines
Typical journey time: 15h 49m

Short answer

We have seen Frontier Airlines fares from St Louis to San Juan. The lowest fare our own searches returned is €126, seen on 10 Oct 2026. October 2026 is the cheapest month in our observations, at €126. These are prices our searches returned on the dates shown, not quotes; run a live search for today's fare.

About this route

Explore the fares we observed from St Louis to San Juan. Prices move often, so pick your dates to see the latest options.

Route distance: 3,231 km
Typical journey time: 15h 49m
Airlines seen: Frontier Airlines, Southern Airways Express, United Airlines
Seen on fares with a connection: Frontier Airlines, United Airlines, Southern Airways Express
Alternative airports: SUS, SIG

Route-level information; individual journeys vary.
We have not observed non-stop service on this route; the fares shown include at least one stop.

A clearer picture of your fare

Observed, not guaranteed

Every price is a fare we actually saw, and it may change at any time.

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The price is final on the provider's site, where your booking is completed.

How our prices work

Airport to city: straight-line distance

St. Louis Lambert International Airport (STL) → St Louis, city gazetteer reference point (38.6270, -90.1994): ≈ 20 km.
Fernando Luis Ribas Dominicci Airport (SIG) → San Juan, city gazetteer reference point (18.4663, -66.1057): ≈ 1 km.
Luis Munoz Marin International Airport (SJU) → San Juan, city gazetteer reference point (18.4663, -66.1057): ≈ 11 km.

Approximate distances calculated from coordinates, not road distances or travel times. These airports serve the city; they are not confirmed endpoints of an offer.

Frequently asked

How much is a flight from St Louis to San Juan?

The lowest fare we have observed is €126, found on 10 Oct 2026. Prices move, so read it as a floor rather than a quote.

When is the cheapest month to fly from St Louis to San Juan?

In our observations October 2026 is the cheapest month so far, at €126.

Are there direct flights from St Louis to San Juan?

Our data holds no non-stop flight from St Louis to San Juan. The fares on this page include at least one stop.

Which airlines fly from St Louis to San Juan?

These are the carriers we have seen on the route: Frontier Airlines, Southern Airways Express, United Airlines.

How long does the flight from St Louis to San Juan take?

The average journey time across the 87 fares we observed is 20h 02m, including any stops. Individual departures vary; the fastest observed flight is listed in the route facts above.

How many of the observed St Louis to San Juan fares were non-stop?

None of the 88 fares we observed was non-stop; every one included at least one stop. That describes our observations, not every flight that operates.

How observed prices work, what "No data" means and what a fare includes: Read the flight price guide