William Diard (April 26, 1924 – March 8, 2009) was an American operatic tenor, teacher, musician, and actor.
At the age of eight he sang with the Paulist Choir in New York, later becoming tenor soloist with "Chanticleer," touring Europe and the Far East.
In 1966, he appeared in the world premiere of Carlisle Floyd's Markheim at the New Orleans Opera (opposite Norman Treigle and Audrey Schuh), later retiring to Hadlyme, CT, where the Diards made appearances and taught in their private studio.
Diard met his wife, Gloria Aliani, while singing a performance of La bohème in 1956 in Miami, Florida.
At Hartt, Diard studied with Virginia and Frederich Schorr (renowned bass-baritone of the Metropolitan Opera).