He began his voice training under Karl Kritz and Arthur Faguy Coté in Fort Worth, followed by studies with Susan Seton and Hulda and Luigi Rossini in New York.
In 1975 he made his debut at San Francisco Opera as Steuermann and Erik in The Flying Dutchman and has sung in sixteen different productions with the company in subsequent seasons.
At San Francisco Opera he was Steva in Jenůfa, Albert Gregor in The Makropulos Affair, Boris in Katya Kabanova, Frank Sargeant in Angle of Repose, and Sergei in Lady Macbeth of Mtsensk.
[7] William Lewis wrote the libretto for Earl Wild's Easter oratorio Revelations as well as singing the role of St. John in its world premiere, conducted by the composer.
Lewis can be seen on DVD in the Metropolitan's 1984 production of Zandonai's Francesca da Rimini, opposite Renata Scotto, Plácido Domingo, and Cornell MacNeil.