Johan Christian Viggo Ullmann (21 December 1848 – 30 August 1910) was a Norwegian educator and politician with Venstre, the Norwegian social-liberal party. He was the son of the author Vilhelmine Ullmann, brother of the feminist Ragna Nielsen and the great grandfather of actress Liv Ullmann. Norway's first social doctor was his grandchild, also named Viggo Ullmann (Lillehammer, 1920–).