Mary Cotton may refer to: Mary Ann Cotton (1832–1873), English convicted murderer Mary Stewart (athlete), or Cotton, (born 1956), British retired middle distance runner Mary Woolley Gibbings Cotton, Viscountess Combermere (1799–1889), Irish author Molly Cotton (Mary Aylwin Cotton; 1902–1984), British archaeologist and doctor
See also Cotton Mary, a 1999 film