Mary Stuart or Mary Stewart may refer to:

People

• Mary Stewart, Countess of Buchan (before 1428–1465), fifth daughter of James I of Scotland, 1st Countess of Buchan
• Mary of Guelders (c. 1434–1463), queen to James II of Scotland
• Mary Stewart, Countess of Arran (1453–1488), daughter of James II of Scotland
• Mary of Guise (1515–1560), wife of James V of Scotland, mother of Mary, Queen of Scots
• Mary, Queen of Scots (1542–1587), queen regnant of Scotland, wife of Francis II of France and mother of James I of England
• Mary Stuart (1605–1607), daughter of James I of England
• Mary Stewart, Duchess of Richmond (1622–1685), British aristocrat
• Mary, Princess Royal and Princess of Orange (1631–1660), Princess Royal and Princess of Orange-Nassau, daughter of Charles I of England and mother of William III of England
• Mary of Modena (1658–1718), wife of James II of Great Britain (VII of Scotland)
• Mary II of England (1662–1694), co-ruler of England and Scotland with her husband William III from 1689 until her death
• Mary Stuart, Countess of Bute (1718–1794), British peeress, wife of the British Prime Minister
• Mary Stewart (social worker) (1862/3–1925), English social worker
• Mary Stewart, Baroness Stewart of Alvechurch (1903–1984), English Labour politician and educator
• Mary Stuart O'Donnell (1607–in or after 1639), Irish noblewoman
• Mary Stewart (novelist) (1916–2014), British novelist
• Mary Stuart (actress) (1926–2002), American actress, best known for her 35-year role in the soap opera Search for Tomorrow
• Mary Stewart (swimmer) (born 1945), Canadian swimmer
• Mary Downie Stewart (1876–1957), New Zealand political hostess and welfare worker
• Mary Stewart (athlete) (born 1956), British middle-distance runner
• Mary Stewart, Viscountess Mountjoy (1654–1720)
• Mary Stuart (academic), vice chancellor of the University of Lincoln
• Marie Stewart, Countess of Mar (died 1644), Scottish courtier
• Mary Ann Sorden Stuart (1828–1893), American suffragist

Works

• Mary Stuart (Schiller play) (1800), a tragic play by Friedrich Schiller based on the life of Mary, Queen of Scots
• Maria Stuarda (1835), a tragic opera by Gaetano Donizetti based on the play by Schiller
• Mary Stuart (Haynes play) (1840), tragedy by James Haynes
• Marie Stuart (opera) (1844), opera by Louis Niedermeyer
• Mary Stewart (play) (1951), anti-romantic five-act play in Scots by Robert McLellan depicting the Queen's downfall in the months between March 1566 and June 1577
• Mary Stuart (film), a 1927 German silent historical film