Born in London, UK, Tonya is the only child of Lloyd G. Williams, a now deceased Supreme Court Justice of the British Virgin Islands and St. Kitts, and Korah H. Williams, a retired Registered Nurse. Both Tonya's parents are Jamaican, but they met in the UK at university and married there. When Tonya was 1½ years old, she and her parents moved to Kingston, Jamaica where her father set up practice. At the age of 4½ while in Jamaica she contracted rheumatic fever and was hospitalized for 6 months. Shortly after that, her parents divorced and her mother returned to the UK with her. They lived in Birmingham, UK where Tonya attended the private schools York House and Greenmoore College. When she was 12 years old, her Mother emigrated them to Oshawa, Canada, a city just outside of Toronto. During high school, Tonya began her career as an actress; at the age of 16 she booked her first TV commercial. After high school she enrolled in Ryerson University's Drama Program in Toronto.