The 2020 Manly-Warringah Sea Eagles season was the 71st in the club's history since their entry into the then New South Wales Rugby Football League premiership in 1947.

After twenty rounds, the team finished 13th on the NRL Ladder.

Due to the COVID-19 pandemic, NRL matches were halted after the second round.

The Sea Eagles were originally meant to play the New Zealand Warriors and Canberra Raiders in Rounds Three and Four, but the NRL announced an updated draw for those rounds on 15 May that gave the Sea Eagles fixtures against the Canterbury-Bankstown Bulldogs and the Parramatta Eels in those rounds.

[1] The Sea Eagles played home games at Central Coast Stadium until the end of round seven where they then returned back to Brookvale.