Letitia Marion Hamilton was born in Dunboyne, Ireland and belonged to a generation of famous Irish women artists. Along with her sister Eva Henrietta Hamilton, she studied under William Orpen at the Metropolitan School of Art in Dublin. She spent some time in Italy but travelled and painted all over the Continent.
Hamilton was most of all a prolific painter of the Irish countryside, and exhibited over 200 paintings at the Royal Hibernian Academy of which she became a member in 1943. Together with Paul Henry, Jack Butler Yeats and others, she formed the Society of Dublin Painters in 1920.