[1][2] Opthof was born in Rotterdam in 1930 and immigrated to Canada in 1949 where he studied classical voice with Catharina Hendrikse.
In 1957, he was awarded a scholarship at the Royal Conservatory of Music and, in 1959, he made his debut as Alcalde in La forza del destino with the Canadian Opera Company (where he remained a member for fifty years, performing in over 75 productions).
He made his Metropolitan Opera debut in 1976, opposite Joan Sutherland as Riccardo, in I Puritani, having previously sung with her on a number of occasions which included being invited to Australia by Richard Bonynge to tour with his wife.
[2] He made some noteworthy recordings of songs by Arnold Schoenberg with Glenn Gould as an accompanist.
[3] Opthof died in Toronto on December 16, 2008, and was survived by his wife Natalia and their three children.