$450 Cheap American Airlines flights St. Louis (STL) to Luxembourg (LUX)

Landing cheap one-way American Airlines flights from STL to LUX from $450 on Expedia couldn't be simpler --- just filter by "Price (lowest to highest)." Or check out our affordable return fares from $673 for your next getaway.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

To discover affordable flights from STL to LUX with American Airlines, start searching about one month before your planned departure. You can save 17% when you book your international tickets 18 to 29 days ahead instead of booking four to five months in advance. Another useful tip? Booking on Sunday can lead to average savings of 17% compared to Friday (the most expensive day).**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Sort your results by "Morning" and "Early Morning" to browse the earliest flights from STL to LUX. Leaving early means flight cancellations are less likely.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.