Born in 1944 at New Glasgow, Nova Scotia, he was the son of Edgar William MacNeil and Elizabeth Adelaide (Weir). A graduate of Mount Allison University and Dalhousie University, MacNeil married Elizabeth Alison Fleming in 1966. He practiced as a family physician in Yarmouth and Sherbrooke, Nova Scotia since 1969.[2]
On December 23, 1988, MacNeil was appointed to the Executive Council of Nova Scotia as Minister of Lands and Forests.[6] When Donald Cameron took over as premier in February 1991, he named MacNeil Minister of Mines and Energy.[7]
In February 1992, MacNeil was shuffled to Minister of Finance.[8] In the 1993 election, MacNeil was defeated by Liberal Ray White in the new Guysborough-Port Hawkesbury riding.[9][10]