Haya Victoria van Someren-Downer, born Gerarda Victoria Downer, (Amsterdam, July 5, 1926 – Rotterdam, November 12, 1980) was a Dutch politician. Representing the People's Party for Freedom and Democracy (VVD), she was a member of the House of Representatives from March 20, 1959, to October 1, 1968, and of the Senate from September 17, 1974, until her death. She also served as party chair from March 29, 1969, to March 15, 1975.