Mary Grace (?–1799/1800) was a British self-taught professional portrait painter and copyist.
Mary Grace may also refer to: Mary Gonzaga Grace (1812–1897), American religious sister and nurse Mary Grace Baloyo (1973–2001), Filipino military aviator Mary Grace Borel (1915–1998), American socialite and film actress Mary Grace Canfield (1924–2014), American theatre-, film-, and television actress Mary Grace Kovar (1929–2015), American statistician Mary Grace Natividad Sonora Poe, full name of Grace Poe (born 1968), Filipino politician, businesswoman, educator, and philanthropist Mary Grace O'Brien (born 1958), American judge Mary Grace Quackenbos (1869–1948), American lawyer HMS Mary Grace, three ships of the Royal Navy