Micah Downs had 18 points and Jeremy Pargo scored 16 for the Bulldogs (25-5), who have won eight straight games to finish 14-0 in the WCC and capture their ninth straight regular-season title, and their 11th in the past 12 years.
Matt Bouldin finished with 11 points, eight rebounds and seven assists, and Steven Gray scored 12 for Gonzaga, which has won the WCC tournament title nine times but fell to San Diego in the championship game last year.
In Monday's title game the Bulldogs will face the winner of Sunday night's semifinal contest between Portland and Saint Mary's.
James Rahon scored 20 for the Broncos (16-17), and John Bryant finished with 13 points and 10 rebounds.
Celebrity Families of 2014 [PHOTOS]