Thomas Thomassen (1878 – 1962) was a Norwegian actor and theatre director. He made his stage debut in 1900 at Centralteatret. He served as theatre director of Stavanger Faste Scene from 1918 to 1921, and of Den Nationale Scene in Bergen from 1925 to 1931.
He chaired the Norwegian Actors' Equity Association from 1915 to 1918, and from 1924 to 1925.
He was the father of actor Knut Thomassen.