Mary John is a feminine given name. Notable people with the name include:
- Mary John Batten (1921âÂÂ2015), Canadian lawyer, judge, and political figure
- Mary John Koothattukulam (1905âÂÂ1998), Malayalam language poet
- Mary John Mananzan (born 1937), Filipino Roman Catholic nun, activist, educator, theologian, and author
- Mary John Sr. (1913âÂÂ2004), Canadian Indigenous leader
- Mary John Thottam (1901âÂÂ1985), Indian Catholic nun and poet