Ross served as the seventh premier of Quebec and later as a member of the Senate of Canada.

He was the son of a Scots-Quebecer merchant, George McIntosh Ross, and his French-Canadian wife Sophie-Éloïse Gouin.

Ross belonged to the Parti bleu and was elected to the Legislative Assembly of the Province of Canada for the district of Champlain in 1861.

He was appointed to the Senate of Canada for the Division of La Durantaye in 1887 and served as Speaker of that institution from 1891 to 1896.

He lost the 1886 provincial election as Leader of the Conservative Party of Quebec but remained in power in a minority government until he resigned on January 25, 1887.