Heather Graham was born in Milwaukee, Wisconsin, the older of two children. Her family is of "three quarters Irish" descent, with her father's side from County Cork. Her younger sister, Aimee Graham, is also an actress and writer. Their mother, Joan (née Bransfield), is a teacher and author of children's books.Their father, James Graham, is a retired FBI agent.The girls were raised with traditional Catholic values. Her family relocated repeatedly before settling down in Agoura Hills, California when she was nine years old.