The 2019–20 season was Rayo Vallecano's 95th season in existence and the club's first season back in the second division of Spanish football. In addition to the domestic league, Rayo Vallecano 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.
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply. Players may hold more than one non-FIFA nationality.
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply. Players may hold more than one non-FIFA nationality.