The Spain national under-21 football team is the national under-21 football team of Spain and is controlled by the Royal Spanish Football Federation. The team, nicknamed La Rojita (The Little Red [One]), competes in the biennial UEFA European Under-21 Championship.

Following the realignment of UEFA's youth competitions in 1976, the Spain under-21 team was formed. Spain has a strong record (competition winners five times and runners-up twice); having consecutively won the 2011 and 2013 Championships. They hold the joint record with Italy for the most wins of the competition.

Since the under-21 competition rules insist that players must be 21 or under at the start of a two-year competition, technically it is an U-23 competition. For this reason, Spain's brief record in the preceding U-23 competitions is also shown, though in actuality, Spain played only three competitive U-23 matches. The first was in the "under-23 Challenge", which they lost, while the next two were in a two-team qualification "group" for the 1972 competition (facing the Soviet Union team, they lost 2–1 at home then drew 1–1 away and failed to qualify. Spain did not enter a team in the other two U-23 competitions, but have been ever present in under-21 competitions).

Spain's youth development programs has been challenging the South American dominance in the FIFA U-17 World Championship and the FIFA U-20 World Cup. In fact, 20 of the Spanish 23-man squad that won the Euro 2008 came through the ranks of the youth teams; most of them had won titles at the youth level as well.

A Seleção Espanhola de Futebol Sub-21, também conhecida como Espanha Sub-21 ou La Rojita, é a seleção de futebol masculino de Espanha para jogadores com idade igual ou inferior a 21 anos. É controlada pela Real Federação Espanhola de Futebol. A equipa compete no Campeonato da Europa de Sub-21 da UEFA e no Torneio Internacional de Toulon.

A seleção espanhola sub-21 é uma das equipas de futebol de jovens mais bem sucedidas do mundo, tendo conquistado cinco títulos do Campeonato da Europa de Sub-21 da UEFA, em 1986, 1998, 2011, 2013 e 2019. A equipe também foi vice-campeã em outras quatro ocasiões, em 1984, 1996, 2000 e 2021.

La Rojita também tem um bom desempenho no Torneio Internacional de Toulon, tendo conquistado três títulos, em 1985, 2002 e 2003. A equipe também foi vice-campeã em outras duas ocasiões, em 1997 e 2006.

Alguns dos jogadores mais famosos que já passaram pela Seleção Espanhola de Futebol Sub-21 são: Raúl, Iker Casillas, Xavi, Andrés Iniesta, Sergio Ramos, David Silva, Thiago Alcântara, Isco, Marco Asensio e Pedri.