She obtained a B.A. in Political Science (with distinction) from Carleton University, then obtained her law degree from Osgoode Hall Law School. She was called to the Bar in 1980.

From 1980 until her appointment to the bench in 1997, Madam Justice Bellamy held a number of progressively more senior positions with the government of Ontario in areas of labour and employment law, criminal law, policing, correctional services.

She was elected a Bencher of the Law Society of Upper Canada and served in this position for 9 years before becoming a judge. She was President of the Federation of Law Societies of Canada, the umbrella organization of the 13 governing bodies of the legal profession in Canada. She was also the Vice-President of the Ontario Centre for Advocacy Training.