Pym was educated at Huyton College, Liverpool, and at St. Hilda's College, Oxford. She worked for the International African Institute in London from 1946 until she retired in 1974 and edited the anthropological journal Africa for more than 20 years. In her novels Pym rejected overt drama and emotionalism and instead chose to depict the quiet, uneventful surface of her characters' lives in order to describe human loneliness and the corresponding impulse to love. Her works include Some Tame Gazelle (1950), Excellent Women (1952), A Glass of Blessings (1958), Quartet in Autumn (1977), and The Sweet Dove Died (1978). A Few Green Leaves (1980) and An Unsuitable Attachment (1982) were published posthumously, as was A Very Private Eye (1984)—her diaries and letters edited as an autobiography.