Pat MacAdam was born in Glace Bay, Nova Scotia and attended St. Francis Xavier University, in Antigonish, Nova Scotia from 1952 until 1956. He served as the editor-in chief of the student newspaper The Xaverian Weekly in 1955, the same year he met longtime friend Brian Mulroney when Mulroney was a freshman and MacAdam was a senior.
MacAdam would serve as a political advisor to Mulroney during his term as Prime Minister of Canada, taking a job at the High Commission of Canada in London.
In addition to his well established weekly column in the Ottawa Sun, MacAdam has written several books, recently Gold Medal Misfits (2007) and Mulroney's Man (2008). His personal book, Big Cy, was nominated for a Stephen Leacock Award in 2007.