Kathleen A. Lahey was the lawyer for three of the B.C. couples who won the right to marry from the B.C. Court of Appeal as of July 8, 2003. She is the author of Are We 'Persons' Yet? Law and Sexuality in Canada (University of Toronto Press, 1999), and has published and consulted on a wide range of legal issues relating to equality and human rights. The founding editor of the Canadian Journal of Women and the Law, she has also served on various advisory boards, including the Sexual Orientation and Gender Identity Committee of the Ontario Bar Association, Egale Canada, the Ontario Advisory Council on Women's Issues, and the Ontario Fair Tax Commission.

She lives in Kingston, Ontario, where she is a professor at Queen's University Faculty of Law.