Jack Costello was the coach of the St. Clair Saints men's hockey team from its inception in 1967 and held the post until 1972-73.

Costello compiled an impressive overall record of 105 wins, 36 losses and 10 ties, including four OCAA championships in six years. His career began with three consecutive undefeated seasons from 1967-70 including capturing the OCAA championship, all three years. He recorded an impressive 18-2 regular season record in 1971-72 and finished off his coaching career in 1972-73, with a 20-3 regular season record and the OCAA championship.

Costello was a founding member of OCAA men's hockey, as well as the Athletic Director for 10 years and the Assistant Athletic Director at St. Clair College for another 10 years.