Slo-Pitch Ontario Association (known as "SPO") was formed in November 1982 in an effort to create more awareness of the sport of slo-pitch and to better communicate with its participants throughout Ontario. In 1992, SPO became a member of Softball Ontario and affiliated with Softball Canada, the officially recognized slo-pitch/softball organizations. Slo-Pitch Ontario has one of the largest provincial memberships in Canada. Slo-pitch softball is one of the fastest growing adult team sports in North America. Over 2,500,000 Canadians play this recreational grassroots game.