Feodor Ivanovich Chaliapin (Russian: Фёдор Ива́нович Шаля́пин, tr. Fyodor Ivanovich Shalyapin, IPA: [ˈfʲɵdər ɪˈvanəvʲɪtɕ ʂɐˈlʲapʲɪn]; February 13 [O.S. February 1] 1873 – April 12, 1938) was a Russian opera singer. Possessing a deep and expressive bass voice, he enjoyed an important international career at major opera houses and is often credited with establishing the tradition of naturalistic acting in his chosen art form.

During the first phase of his career, Chaliapin endured direct competition from three other great basses: the powerful Lev Sibiriakov (1869–1942), the more lyrical Vladimir Kastorsky (1871–1948), and Dmitri Buchtoyarov (1866–1918), whose voice was intermediate between those of Sibiriakov and Kastorsky. The fact that Chaliapin is far and away the best remembered of this magnificent quartet of rival basses is a testament to the power of his personality, the acuteness of his musical interpretations, and the vividness of his performances.