Theodore Kosloff (born Fyodor Mikhailovich Kozlov, Russian: Фёдор Михайлович Козлов; January 22, 1882 – November 22, 1956) was a Russian-born ballet dancer, choreographer, and film and stage actor.

After arriving in the United States in 1909, Kosloff was introduced to influential film director Cecil B. DeMille by the actress and writer Jeanie MacPherson.

DeMille was also encouraged to sign Kosloff due to the persistence of his young niece Agnes de Mille, who was an ardent fan of the ballet dancer.

By December 1912, Kosloff was reported to be the choreographic director of La Saison Russe, preparing a short run of American premiers of operas and ballets for Spring 1913 in New York, in coordination with Morris Gest.

The pre-season announcement promised Mussorgsky's Khovanshchina and Boris Godunov, Rimsky-Korsakov's Sadko and The Tsar's Bride, Anton Rubinstein's Demon, Alexander Borodin's Prince Igor and Mikhail Glinka's Ruslan and Lyudmila.

[4] He traveled to New York City in February of that year,[5] where he saw his brother and fellow dancer Alexis Kosloff and met with representatives of the Liberal party of Kazan.

With his dark hair and complexion, the ballet dancer was often cast in more exotic roles, often as a "Latin lover" type, Eastern European prince or noble, or Arabic sheik.