The Calder Memorial Trophy is an annual award given "to the player selected as the most proficient in his first year of competition in the National Hockey League (NHL)." It is named after Frank Calder, the first president of the NHL. Serving as the NHL's Rookie of the Year award, this version of the trophy has been awarded since its creation for the 1936–37 NHL season. The voting is conducted by members of the Professional Hockey Writers' Association at the conclusion of each regular season to determine the winner.

Frank Sellick Calder was a British-born Canadian ice hockey executive, journalist, and athlete.