Christian Martin Julius Frauenstädt (April 17, 1813, Bojanowo, Posen – January 13, 1879, Berlin) was a German philosopher and editor.
He was educated at the house of his uncle at Neisse, and converted from Judaism to protestant Christianity in 1833.
He became a private lecturer and scholar in 1848 in Berlin, where he would become the primary editor and interpreter of Schopenhauer's philosophy.
[2][3] Schopenhauer made Frauenstädt his literary executor to edit his works, calling him indefatigabilis (unwearying).
Frauenstädt participated in contemporary debates over materialism in his 1855 and 1856 books and pessimism in his works on Schopenhauer.