He came from a family of politicians and lawyers; his father later became Premier of Quebec and his grandfather, Jean-Thomas Taschereau, was on the Supreme Court of Canada.

[1] Following a career as a lawyer, Taschereau entered politics as a Liberal and won a seat in the Quebec National Assembly in 1930.

[citation needed] On February 9, 1940, he was appointed to the Supreme Court of Canada, filling the vacancy created by the death of his former law partner, Lawrence Cannon.

[citation needed] In 1946, he and fellow Justice Roy Kellock conducted the Royal Commission on Spying Activities in Canada that had been prompted by the Gouzenko Affair.

[citation needed] Robert Taschereau died in 1970 at the age of 73, and was interred in the family plot at the Cimetière Notre-Dame-de-Belmont in Sainte-Foy, Quebec.