Otto Ludvig Sinding (20 December 1842 – 22 November 1909) was a Norwegian painter, illustrator, poet and dramatist. Sinding drew on motives from Norwegian nature, folk life and history.

Otto Sinding was born in Kongsberg as a son of mine superindendent Matthias Wilhelm Sinding (1811–1860) and Cecilie Marie Mejdell (1817–86). He was the older brother of the sculptor Stephan Sinding and the composer Christian Sinding. He was a nephew of Nicolai Mejdell (1822–1899) and Thorvald Mejdell (1824–1908), and through the former a first cousin of Glør Thorvald Mejdell, who married Otto's sister Thora Cathrine Sinding.[2] Otto Sinding was also a first cousin of Alfred Sinding-Larsen and the three siblings Ernst Anton Henrik Sinding, Elisabeth Si...