Gilles Pouliot served as reeve for the Township of Manitouwadge for six years. He also worked as a flotation operator for Noranda Mines.

He served as a member of the Legislative Assembly of Ontario from 1985 to 1999, representing the Northern Ontario riding of Lake Nipigon for the New Democratic Party. He was elected in the 1985 provincial election, defeating Progressive Conservative candidate Jim Files by over 1,200 votes. He was re-elected by greater margins in the provincial elections of 1987 and 1990.

The NDP won a majority government in the 1990 election, and Pouliot was named as Minister of Mines and Minister responsible for Francophone Affairs in Bob Rae's government on October 1, 1990. In early 1991, he introduced legislation forcing mining companies to renew their claims or risk losing them. He retained responsibility for Francophone Affairs throughout the Rae government. On July 31, 1991, he was transferred from Mines to the Ministry of Transportation. On October 21, 1994, near the end of the Rae government's time in office, he was shifted back to Northern Development and Mines.