Mary Grant may refer to:

• Mary Grant Price (1917–2002), American costume designer
• Mary Grant (politician) (1928–2016), Ghanaian politician
• Mary Grant (sculptor) (1831–1908), British sculptor
• Mary K. Grant (1902–1975), American industrial designer
• Mary E. Grant (born 1953), American psychiatric nurse and politician
• Mary Pollock Grant (1876–1957), Scottish suffragette, politician, missionary and policewoman
• Mary Grant (archer) (born 1949), Canadian former archer
• Mary Goodell Grant (1857–1941), American socialite and first lady of Colorado
• Maria Rosetti (1819–1893), née Marie Grant, Guernsey-born Wallachian and Romanian political activist, journalist, essayist, philanthropist, and socialite
• Mary Seacole (1805–1881), née Mary Grant, Jamaican-born woman of Scottish and Creole descent who set up a 'British Hotel' behind the lines during the Crimean War
• Liz Grant (Mary Elizabeth Grant, born 1930), Australian former pharmacist and politician
• Mary Grant in Jules Verne novel In Search of the Castaways

• Mary Grant Bruce (1878–1958), Australian children's author and journalist
• Mary Grant Carmichael (1851–1935), English composer
• Mary Grant Roberts (1841–1921), Australian zoo owner