Lazar Klyuzner, who also performed under the pseudonym Lavrovsky, was a Russian opera singer and music teacher. He was born in Simferopol in 1872 and was the father of the composer Boris Klyuzner.
The son of Iosif-Ber Leyzerovich Klyuzner, he graduated from the St. Petersburg Conservatory in 1900, where he studied with Antonio Cotogni and Stanislav Gabel. He sang in St. Petersburg at the People's House Opera from 1900 to 1902 and at the Arcadia Theatre in 1903, and also performed in Vitebsk, Minsk, and Tiflis.
From 1904, Klyuzner taught voice at the music school in Astrakhan. His students included Nikolai Bravin. He was shot in the street during revolutionary unrest in Astrakhan in 1918.
His wife, Lyubov Klyuzner, née Gordel, was an artist. Their son Boris Klyuzner (1909–1975) became a composer.