Born and raised in Vancouver, Tim holds a BA (UBC), MA (Spirituality) (HNC California) and M. Divinity (Vancouver School of Theology). He is a former airline employee.

Tim worked in the Philippines and South Africa where he was one of the Canadian representatives at the African National Congress Conference in Durban in 1991 where Nelson Mandela was elected as the ANC's party president. While in South Africa, Councillor Stevenson worked with the emerging Black Liberation Gay and Lesbian Movement. He was also one of the International observers in the South African elections in 1994.

Tim is a former Member of the Legislative Assembly for Vancouver-Burrard, British Columbia. He is Canada's first openly gay minister (appointed Employment and Investment Minister, 2000) of a provincial cabinet, for the New Democratic Party.

He is the first openly gay minister ordained by the United Church of Canada (1992). Prior to being first elected he was Minister at St. Paul's United Church. Tim also teaches Comparative Religions (Islam, Christianity, and Judaism) in the Religious Studies/Art History Department at Langara College in Vancouver.

Tim now lives in the West End of Vancouver with Gary Paterson, his partner of twenty-two years, who is also a United Church minister. Together they have raised three daughters, now all in their twenties.