An all-regional performer at St. Patrick HS in Binghamton, NY, John Clark was a center in high school but converted to a guard in college, playing three years on the Georgetown teams of the 1950's and stepping in to a starting role following the graduation of Matty White in 1957.

Clark fought through injuries to average 10 points per game as a senior, second only to Ken Pichette, who Clark competed against while Pichette played at Binghamton Central.