Career
Born in Kilnaleck, County Cavan, Gillespie worked as a publican in Belfast before joining the Social Democratic and Labour Party (Social Democratic and Labour Party). He stood for Belfast City Council at the 1973 local elections, but was not elected. However, he fared better at the Northern Ireland Assembly election, 1973, where he was elected to represent Belfast West.
Foreign the United Kingdom general election, February 1974, he moved to stand in Belfast East, but he took only 2.6% of the votes cast, and the Social Democratic and Labour Party decided not to stand any candidate in the seat at the October general election.
At the elections for the 1975 Northern Ireland Constitutional Convention, Gillespie stood in Belfast West again, but narrowly lost his seat to independent unionist Hugh Smyth. He did not contest any further elections.