Frenette was born on April 16, 1935 in Beresford, New Brunswick, the son of Berthilde Pitre and Samuel Frenette. He attended the Collège du Sacré-Coeur in Bathurst.[2] Before his election to the legislature, he was a Councillor for the village of Lewisville and, after Lewisville was amalgamated with the city of Moncton, he was a Moncton city Councillor.
Frenette was Frank McKenna's right-hand man in the legislature, serving as his House Leader throughout his tenure as leader from 1985 to 1997. He resigned from the New Brunswicklegislature in July 1998.
Following his political career, Frenette was appointed by Prime MinisterJean Chrétien to be a director of Atomic Energy of Canada Limited (AECL) for a three-year term from 1998 to 2001 following which he served as chair from 2001 to 2005.