Otto Valstad (11 December 1862 – 20 June 1950) was a Norwegian educator, painter, book illustrator and children's writer.

He was a student at the Norwegian National Academy of Craft and Art Industry under Johan Nordhagen and later briefly attended Académie Julian in Paris during 1897.

Otto and Tilla Valstad were avid art collectors and their home in Hvalstad became a cultural centre.

His works are displayed at Asker Museum together with an extensive collection of art and cultural-historical objects.

He is represented in the National Gallery of Norway with the portrait Fru Lina Brun from 1901.