A native of Vernon, B.C., Pospisil moved to the singles final with a 6-3, 6-4 win over No. 6 seed Jimmy Wang of Taiwan on Saturday.
"It was a tough match, especially here because the courts are playing pretty fast and low so obviously when you play somebody like Jimmy who's hitting the ball very flat and hard, it's difficult," Pospisil said. "I was just trying to hang in there, I was battling, and I'm really happy to get this win because he's an extremely tough player."
Pospisil, 22, has not lost a set all week. He will play Daniel Evans of Great Britain in Sunday's final.
On the women's side, Toronto's Sharon Fichman, 22, rallied after dropping her first set to knock off Barbora Zahlavova Strycova of the Czech Republic 1-6, 6-4, 6-4.
"I tried lobbing a lot at one point, tried to break the rhythm and eventually I found my groove," Fichman said. "Late in the second set, I just started playing better, the match got closer, I fought really hard and am just happy to pull through."
Fichman will face 22-year-old Johanna Konta of Great Britain in Sunday's women's singles final. If the Canadian wins, she will walk away from the VanOpen with two titles.
Earlier in the day, Fichman and doubles partner Maryna Zanevska of Ukraine defeated Americans Jacqueline Cako and Natalie Pluskota to win the women's doubles title.
Toronto's Adil Shamasdin and American partner James Cerretani will face Jonathan Erlich and Andy Ram of Israel in Sunday's men's doubles final. Shamasdin and Cerretani advanced with a 6-3, 6-3 semifinal win over Tatsuma Ito and Hiroki Moriya of Japan.