Rayo Vallecano de Madrid, commonly known as Rayo Vallecano, was founded in 1924 and is a professional football club based in Vallecas, Madrid, Spain. Its nickname is "The Lightning". The club's first president was Prudencia Prego, wife of Julián Huerta.
In the 1980s and 1990s, the club constantly fluctuated between the first and second divisions. In the 1998-1999 season, the team showed significant improvement. In 2001, the club had its most glorious year, performing well in the UEFA Cup, but was eventually eliminated by Alavés. In 2011, after struggling for many years, the club defeated Real Betis in the promotion playoffs and successfully returned to La Liga.
In July 2015, the club officially announced the loan of Zhang Chengdong, a national team-level winger, from Beijing Guoan. The agreement was a 1+1 year loan contract. This young man from Baoding, Hebei, became the first player from China to play in the Spanish Primera División. In the 2022 Copa del Rey quarter-finals, the team achieved a surprising 1-0 victory at home against the eventual La Liga champions, Real Madrid, creating a historic moment for the club and reaching the semi-finals once again.