The 2019–20 season was Club Deportivo Leganés' 79th season in existence and the club's 4th consecutive season in the top flight of Spanish football. In addition to the domestic league, Leganés participated in this season's edition of the Copa del Rey. The season was slated to cover a period from 1 July 2019 to 30 June 2020. It was extended extraordinarily beyond 30 June due to the COVID-19 pandemic in Spain.