Arnold Ludwig Mendelssohn (26 December 1855 in Racibórz – 18 February 1933 in Darmstadt), was a German composer and music teacher. He was born in the then Ratibor, Province of Silesia, son of Felix Mendelssohn's cousin Wilhelm Mendelssohn (1821–1866) who had married in 1854 Louise Aimee Cauer (sister to Bertha Cauer). Arnold Ludwig himself married in 1885 his second cousin Maria Cauer, daughter of Carl Cauer (brother of Ludwig Cauer).