The Luxembourg national under-21 football team is the national representative under-21 football team of Luxembourg. It is controlled by the Luxembourg Football Federation (FLF). The team is the feeder team to the Luxembourg's national team. The team competes in the biennial European Under-21 Championship. Since the establishment of the UEFA European Under-21 Football Championship in 1978 the team has always finished bottom of their qualification group.

The team is for Luxembourgian players aged under 21 at the start of the calendar year in which a two-year European Under-21 Football Championship campaign begins, so some players can remain with the squad until the age of 23. As long as they are eligible, players can play for Luxembourg at any level, making it possible to play for the U21s, senior side, and again for the U21s. This has been the case for several senior team players like Billy Bernard, Lars Gerson and Maurice Deville. In their history they have only ever won two qualification games. Their first win occurred in their 1986 UEFA European Under-21 Football Championship qualification campaign where they defeated Belgium 3–1. Their second victory came in a 2011 UEFA European Under-21 Football Championship qualification Group 3 away game against Bosnia and Herzegovina in a 1–0 win.

Luksemburgi U21 jalgpallikoondis on Luksemburgi alla 21-aastaste meeste jalgpallikoondis. Meeskonda haldab Luksemburgi Jalgpalliliit ja see esindab Luksemburgi rahvusvahelistel alla 21-aastaste jalgpallivõistlustel.

Meeskond osaleb UEFA Euroopa alla 21-aastaste meistrivõistlustel alates turniiri loomisest 1978. aastal. Siiski ei ole Luksemburg U21 kunagi finaalturniirile pääsenud.

Meeskonna kodustaadion on Stade Josy Barthel Luksemburgis. Praegune peatreener on Manuel Cardoni.