Gwyneth (sometimes Gweneth or Gwynyth) is a Welsh feminine given name which derives from the kingdom of Gwynedd. Notable people:

• Gwyneth Boodoo, American psychologist and expert on educational measurement
• Gwyneth Cravens, American novelist and journalist
• Gwyneth Dunwoody (1930–2008), Member of Parliament in the United Kingdom
• Gwyneth Glyn (born 1979), Welsh language poet and musician
• Gwyneth Herbert (born 1981), British singer-songwriter and composer
• Gwyneth Ho (born 1990), Hong Kong social activist and former journalist
• Gwyneth Hughes, British screenwriter and documentary director
• Mabel Gweneth Humphreys, mathematician
• Gwyneth Johnstone (1915–2010), English landscape painter
• Gwyneth Jones (novelist) (born 1952), British science fiction and fantasy writer and critic
• Gwyneth Jones (soprano) DBE (born 1936), Welsh soprano
• Gwyneth Lewis (born 1959), Welsh poet, first National Poet for Wales
• Gweneth Lilly (1920–2004), Welsh writer and teacher
• Gweneth Molony (born 1932), Australian figure skater
• Gwyneth Paltrow (born 1972), American actress and businesswoman.
• Gwyneth Powell (1946–2022), English actress
• Gwyneth Rees (born 1968), British author of children's books
• Gwyneth Scally, visual contemporary artist from Tucson, Arizona, United States
• Gwyneth Stallard, British mathematician
• Gwyneth Strong (born 1959), English actress
• Gwyneth Walker (born 1947), American composer
• Gwenethe Walshe (1908–2006), British dancer
• Gwynyth Walsh (born 1956), Canadian actress
• Gweneth Whitteridge, medical historian

Gwyneth is also the name of the following fictional characters:

• a character in the Fur Fighters video game
• the title character of Gwyneth and the Thief, a young adult historical romance novel written by Margaret Moore
• Gwyneth, a character in the Dragonlance novel The Legend of Huma
• Gwynneth, an Australian Masked Owl from the Wolves of the Beyond fantasy novel series by Kathryn Lasky