Rex may refer to:

  • Adam Rex (born 1973), American illustrator and author of children's books
  • George Rex (1765–1839), British-born entrepreneur
  • Isaac Rex, American football player
  • Jim Rex (born 1941), the 16th and current South Carolina Superintendent of Education
  • John Rex (1925–2011), British sociologist
  • Knud Rex (1912–1968), Danish stage and film actor
  • Ludwig Rex (1888–1979), German film actor of the silent era
  • Marcus Rex (1886–1971), the last British Resident of Perak during the World War II waged in British Malaya
  • Rico Rex (born 1976), former German pair skater
  • Robley Rex (1901–2009), World War I-era veteran and, at the age of 107, one of two remaining U.S. veterans related to the First World War
  • Simon Rex (born 1974), American actor and comedian
  • Theresa Rex, Danish actress and singer