He entered politics in 1965 as a town councillor and deputy mayor in
Middleton, Nova Scotia. Sheehy moved to provincial politics in
1970, when he was elected MLA for Annapolis East. He was re-elected in the
1974 election. Sheehy was re-elected by almost 1400 votes in the
1978 election, that resulted in a majority government for the Progressive Conservatives led by
John Buchanan. On October 5, 1978, Buchanan appointed Sheehy to the
Executive Council of Nova Scotia as Minister of Agriculture and Marketing and Minister of Health. In June 1979, Buchanan shuffled his cabinet, with Sheehy moving to Registrar General and remaining as Minister of Health. Sheehy was re-elected in the
1981 and
1984 elections. Sheehy continued to serve in cabinet until November 1985, when he asked to be shuffled out for family reasons. He also indicated he would not run in the next election. ==Later life and death==