Otto Eugen Schulz (31 October 1874 – 17 February 1936) was a German botanist, born in Berlin. He was the brother of botanist Roman Schulz (1873-1926).
He published important systematic treatments of the families Brassicaceae (then known as Cruciferae) and Erythroxylaceae, and he is the authority for numerous species within these families. He was the author of a 1903 treatise on the genus Cardamine (family Brassicaceae), titled "Monographie der Gattung Cardamine".
The genus Ottoschulzia (family Icacinaceae) was named in his honor by Ignatz Urban (1848-1931).