Ensemble member of the Berlin State Opera (1898-1900), the Vienna State Opera (1901-1926). Retired from opera in 1934 to devote his time to film acting.
First known as an operatic tenor, especially renowned for his Wagnerian work, he would eventually quit singing and become a comedian in Austrian films.
He had his last great success as sultan Abdul-Hamid in the movie "Münchhausen" (1943).
His most famous performances he had as a Verdi and Wagner singer.
His children Walter Slezak as an actor and Margarete Slezak as a singer continued the artistic tradition of the family.
After an education as a gardener and locksmith he made his debut as a singer in Brünn in 1896 and launched from 1901 an unique career at the Wiener Staatsoper.
In 1926 he became an honorary member of this opera house.
The singer and actor Leo Slezak was one of the most popular tenors at the beginning of the 20th century.
Leo Slezak conquered the big screen in 1932 and impersonated often funny characters.
He was appointed a Kammersänger in 1905 had he had great successes at the New York Metropolitan Opera from 1909 to 1912.