The top-seeded Raonic earned another trip to the San Jose title match with a 6-4, 6-2 defeat of No. 3 seed Sam Querrey of the United States.
Haas reached the final with a 6-3, 6-4 win over second-seeded American John Isner in the day's first semifinal.
Should Raonic prevail Sunday, he would become the first player to win the San Francisco-area event three consecutive times in the Open Era.
Haas is seeking his 14th career ATP Tour win, and first since the 2012 tournament in Halle, Germany.
Swim Week Miami Beach 2014 [PHOTOS]