Born in Kirkland Lake, Ontario, Slater began his career in 1958 at St. Lawrence University, where he was a two time All American, and played hockey in the National Collegiate Athletic Association.
Two years later he accepted a job at the Des Moines Oak Leafs, where he worked again as a head coach, reaching the team twice in a row to qualify for the playoffs.
In season 1972/73 he was appointed to the newly formed World Hockey Association and became a coach with the Los Angeles Sharks.
In 2013, the documentary "The General" was made, which chronicles Terry Slater and the improbable story of the 1989-1990 Colgate University Men's Ice Hockey Team run to the ECAC Championship and Division I NCAA Finals.
Featured in the documentary were players Karl Clauss, Joel Gardner, Steve Spott, Grant Slater, as well as assistant coach Brian Durocher and Student Assistant Eric Opin, retired SID Bob Cornell, and numerous Village of Hamilton, New York residents.