The 2020–21 Peterborough United F.C. season was the club's 87th season in their history and the eighth consecutive season in EFL League One, Along with League One, the club also participated in the FA Cup, EFL Cup, and EFL Trophy. The season covers the period from 1 July 2020 to 30 June 2021. With a 3–3 draw against Lincoln City on 1 May 2021, Peterborough secured automatic promotion to the Championship, making a return to the second division after an eight-year absence.