Ryan helped to organize a United Steelworkers of America (USWA) local where he worked shortly after arriving in Canada. He has been a Canadian Union of Public Employees (CUPE) activist since he went to work for Ontario Hydro in 1976. He served as CUPE Ontario president from 1992 to 2009, representing 225,000 workers in the public sector. CUPE Ontario added 75,000 new members under Ryan's leadership. CUPE is the Canada's largest and fastest growing union with nearly 600,000 members. CUPE Ontario is the largest provincial division. Ryan also served as general vice-president of CUPE National until 2009.