The 2018 Ontario Scotties Tournament of Hearts, the provincial women's curling championship for Southern Ontario, was held January 10 to 14 at the Whitby Curling Club in Whitby, Ontario. The winning team represented Ontario at the 2018 Scotties Tournament of Hearts in Penticton, British Columbia. The event had a triple knock out format, rather than the traditional round robin event as was done in previous years. The number of qualified teams increased from 8 to 12.