Alexander Leonidovich Yanshin (; 1911, Smolensk - 1999, Moscow) was a Soviet Russian geologist, Academician of the USSR Academy of Sciences (since 1958). From 1982 to 1988, Yanshin served as vice-president of the USSR Academy of Sciences. From 1967, Yanshin served as president of the Moscow Society of Naturalists.
His father was a lawyer. He studied at the Moscow State University.
He received the Candidate's degree from the USSR Academy of Sciences in 1937. In 1952, he defended his doctoral dissertation. He was elected a Member of the USSR Academy of Sciences in 1958.