Gladwin is an English surname derived from the Middle English name Glad(e)wine (or Gledwine), which is composed of words meaning "cheerful" and "friend". Notable people with the surname include:
Chris Gladwin (cricketer) (born 1962), English cricketer
Chris Gladwin (engineer) (born 1964), American engineer and entrepreneur
Cliff Gladwin (1916–1988), English cricketer
Derek Oliver Gladwin, Baron Gladwin of Clee (1930–2003), British trade unionist
George Gladwin (1907–?), English footballer
Harold S. Gladwin, American archaeologist, anthropologist and stockbroker
Henry Gladwin (1729 or 1730–1791), British military leader
Joe Gladwin (1906–1987), British actor
John Gladwin (born 1942), Bishop of Chelmsford in the Church of England
Mary E. Gladwin (1861–1939), American nurse
Phil Gladwin, television writer and script editor
Thomas Gladwin (musician) (1710–1799), English composer and musician
Thomas Gladwin (sheriff) (1629/30–1697), Sheriff of Derbyshire
Walter Gladwin (1902–1988), New York City politician