Friedrich Julius Richelot (6 November 1808 – 31 March 1875) was a German mathematician, born in Königsberg.

He was a student of Carl Gustav Jacob Jacobi.

He was promoted in 1831 at the Philosophical Faculty of the University of Königsberg with a dissertation on the division of the circle into 257 equal parts (see references) and was a professor there.

Richelot authored numerous publications in German, French and Latin, among them — with his 1832 dissertation — the first known guide to the Euclidean construction of the regular 257-gon with compass and straightedge.

In 1825, he joined the Corps Masovia.