Carl Gustav Jacob Jacobi (10 December 1804 – 18 February 1851) is a German mathematician, who makes fundamental contributions to elliptic functions, dynamics, differential equations, and number theory.

His name is occasionally written as Carolus Gustavus Iacobus Iacobi in his Latin books, and his first name is sometimes given as Karl.

Jacobi is the first Jewish mathematician to be appointed professor at a German university.