Otto Robert Nowak was an Austrian history , genre and portrait painter.

Nowak graduated from the General Drawing School, was a guest student at the Vienna Academy in 1891 and, from 1893, a full student at the General School of Painting under Julius Berger. He also studied at the master school for history painting under Siegmund L'Allemand and Franz Rumpler.

He was friends with the Austrian architect Max Hegele. Hegele had a house in Weidlingau near Vienna in which Otto Nowak and his wife Hedi Nowak-Reimer spent many summers. Both artists were members of the Vienna Künstlerhaus.