Portia H. Willis (c.1887–7 July 1970) was an American suffragist, pacifist, lecturer, activist and organiser of the early 20th-century.
She was educated at the Anne Brown School and attended, though did not graduate from, Columbia University and Harvard College.
Her relatively high profile, the circumstances of her birth into a well known political family, and the nature of newspaper reporting of the day gave rise to frequent press coverage earning her the soubriquet of "The Prettiest Suffragette in New York State".
Other of her memberships include the New York Board of the Women's International League for Peace and Freedom, and the Round Table on the United Nations, which she chaired from 1950 to 1953.
She married two or three times: first to Captain L. Rodney Berg in 1925 until his death in 1941, taking the name Portia Willis-Berg.