The Canucks selected Juolevi fifth overall in the June draft, making him one of three Finns to go in the top five.
The 18-year-old finished third among Ontario Hockey League rookie defensemen in scoring last season with 42 points on nine goals and 33 assists in 57 games for the Memorial Cup champion London Knights. He also helped Finland win the 2016 world junior championship.
"Olli is a talented all-around defenseman with high hockey sense who will be a big part of our organization's future," Canucks general manager Jim Benning said in a statement. "He's had an outstanding year, winning the Memorial Cup and world junior gold. We look forward to seeing him continue his development and compete at the NHL level during training camp in September."