Born near Quebec City in 1916, Simoneau studied in Montreal and began his career there with the company Vari_t_s Lyriques. It was during this period that he met his wife and frequent performing partner, soprano Pierrette Alarie.
In 1949 he first sang in Paris, and he went on, over the next two decades, to an acclaimed career including appearances at La Scala, the Vienna State Opera, the Teatro Col‹n, Lyric Opera of Chicago and the Metropolitan Opera; among the great conductors with whom he worked were Bruno Walter, Thomas Beecham and Herbert von Karajan.
The CBC's obituary mentions one particularly historic performance in Paris, at the Festival du XXe Sicle in 1952, when he sang in Stravinsky's Oedipus Rex with the composer conducting and Jean Cocteau as the narrator. The following year, according to The Canadian Encyclopedia, Simoneau portrayed Tom Rakewell in the French premiere of Stravinsky's The Rake's Progress.
His final performance as a soloist was in Handel's Messiah with the Montreal Symphony in 1970.
Following his retirement from the stage, according to the CBC, Simoneau became the first creative director of the Op_ra du Qu_bec and later took teaching positions at the San Francisco Conservatory and the Banff School of Fine Arts. In 1982 he and Alarie moved to Victoria, the capital of British Columbia, where they founded Canada Opera Piccolo, an advanced training program for young singers.
In 1990 France named Simoneau an Officer of the Ordre des arts et des letters, and in 1995 he and Alarie were named Companions of the Order of Canada, one of the nation's highest civilian honors.
"He had a particular style, faultless technical control," Timothy Vernon, artistic director of Pacific Opera Victoria, told the AP, "He pushed himself right to the wall to develop a technique that was completely at his control and completely able to express what he felt. [...] He was without doubt one of the most accomplished singers we [in Canada] have ever produced."