Olaf Fredrik Watnebryn (4 November 1908 - 6 June 1977) was a Norwegian politician for the Labour Party.
He was elected to the Norwegian Parliament from the Market towns of Buskerud county in 1945, and was re-elected on four occasions.
Watnebryn was born in Drammen and a member of Drammen city council in 1934 - 1937, and of its executive committee in the periods 1937 - 1940 and 1945 - 1947. His career in politics ended with the post of County Governor of Buskerud, which he held from 1962 to 1969.