The club was officially founded on 23 June 1928 by Félix Pérezde la Serna. Its first president was Ramón del Hierro. However the club had to suspend operations in 1936 due to the Spanish civil war, where they remained inactive until they reformed on 4 September 1946. Leganés played the vast majority of its existence in the lower leagues. In 1977 the club regained promotion to the fourth division, where it had played before for seven years when the category was still the third level. After a steady progression, Leganés reached the new division three in 1987, being promoted to the second division six years later and maintaining its league status for 11 seasons; during this timeframe, it collected two consecutive eighth places from 1995–97. In the 2013–14 season, Leganés promoted to second division after 10 years in third division. In the 2015–16 season, for the first time in their history, Leganés earned promotion to La Liga, which was sealed on 4 June 2016 with a 1–0 away win against CD Mirandés. They remained in the top flight for four seasons, reaching a peak of 13th in 2018–19, before relegation in the last game of the following season, a 2–2 home draw with Real Madrid. Ending Lega's four-year stint in the first tier. During this spell, the team qualified for the first time to the semifinals of the Copa del Rey, by eliminating Real Madrid in the quarterfinalsthanks to a 2–1 win at Santiago Bernabéu Stadium.
Fans
The fans have friendly relation with ultras group Gate 12 of Egaleo FC, the towns of Egaleo and Leganés happen to be twinned too. Their biggest rival is Getafe with whom they contest the South Madrid derby.
