A statement from the opera says Wenkoff died Monday in his Upper Austrian home town of Bad Ischl. No cause of death was given.
Born Sept. 23, 1928, in the Bulgarian city of Veliko Tarnovo, Wenkoff studied law and worked as a lawyer before embarking on a singing career, first in operettas and then as an opera performer in Bulgaria and East Germany.
He moved to Richard Wagner's operas from the Italian repertoire, and his international breakthrough came in 1975 as Tristan in Wagner's "Tristan and Isolde." Engagements at the Bayreuth Festival, the Berlin State Opera, the Metropolitan Opera in New York and other famed opera houses followed.
Funeral arrangements were not announced.