Joslyn may refer to:

  • Allyn Joslyn (1901–1981), American stage, film and television actor
  • Betsy Joslyn (born 1954), Broadway musical and dramatic actress and soprano
  • Cliff Joslyn (born 1963), American information systems scientist
  • Frank Joslyn Baum (1883–1958), lawyer, soldier, writer, and film producer
  • Joslyn Hoyte-Smith (born 1954), former British 400m athlete
  • Joslyn Musey, the protagonist of the science fiction novel Warchild by Karin Lowachee
  • Marcellus L. Joslyn (1873–1963), founder of the Joslyn Manufacturing and Supply Company, a Chicago, Illinois electrical supply firm
  • Matilda Joslyn Gage (1826–1898), suffragist, Native American activist, abolitionist, freethinker, and prolific author
  • Maynard A. Joslyn (1904–1984), Russian-born American food scientist in the rebirth of the California wine industry after 1933
  • Steve Joslyn, American college baseball coach
  • Joslyn Art Museum, the principal fine arts museum in the state of Nebraska, United States of America
  • Joslyn Castle, folly located at 3902 Davenport Street in the District of Omaha, Nebraska, USA