The Bulldogs bounced back from a non-conference loss to Butler last weekend that ended an eight-game winning streak.
Gonzaga raced to a 40-21 halftime lead and shot 56 percent for the game to stay out front in the West Coast Conference.
Olynyk made all nine of his field goal attempts and was perfect in nine free throw tries. Elias Harris added 24 points for the Bulldogs (18-2, 5-0 WCC). Josh Sharp and Brandon Davies paced the Cougars (15-6, 5-2) with 14 points each.