The 1970 Calder Cup playoffs were the inaugural edition of the playoffs.
- First round
- Montreal Voyageurs defeated Baltimore Clippers 4 games to 1.
- Buffalo Bisons defeated Quebec Aces 4 games to 2.
- Springfield Kings defeated Hershey Bears 4 games to 3.
- Second round
- In double round-robin, Buffalo Bisons and Springfield Kings advanced. Montreal Voyageurs eliminated after third loss.
- Buffalo Bisons defeated Springfield Kings 4 games to 0, to win the Calder Cup.