The No. 1 pick in the draft was the unanimous pick as No. 1 rookie this season.
Schaefer rewrote the record book in his first NHL season. His 59 points in 82 games were the most ever by an 18-year-old rookie defenceman, and he was the first defenceman in more than 90 years to lead all rookies in goals, with 23.
The Hamilton, Ont., native is the sixth Islander to win the Calder Trophy, joining Mat Barzal (2018), Bryan Berard (1997), Mike Bossy (1978), Bryan Trottier (1976) and Denis Potvin (1974).
At 18 years, 223 days on the final day of the regular season, Schaefer became the youngest winner in NHL history, one day younger than Colorado Avalanche centre Nathan MacKinnon was when he won in 2014 (18 years, 224 days).
The other finalists for the award were forwards Ivan Demidov of the Montreal Canadiens and Beckett Sennecke of the Anaheim Ducks.
Schaefer earned the award with 198 first-place votes.
