Smithson or Smythson is an English surname and (less often) a given name.

Notable people bearing the name include:

• Alison and Peter Smithson, 20th-century British architects
• Robert Smythson, 16th-century English architect, father of architect John Smythson, and grandfather of architect Huntingdon Smithson

• Annie M. P. Smithson, novelist
• Robert Smithson, American artist
• Carly Smithson, singer
• Florence Smithson, singer and actor
• Harriet Smithson, also known as Henrietta Constance Smithson, actor and wife of Hector Berlioz
• Henry Smithson, the musician Riton

• Hugh Smithson, (1714–86) later Hugh Percy, 1st Duke of Northumberland
  • the Smithson baronets
• Smithson E. Wright, 16th mayor of Columbus, Ohio

• James Smithson, British scientist, eponym of the Smithsonian Institution
• Smithson Tennant, chemist

• Bryan Smithson, American basketball player
• Fish Smithson, former NFL player
• Forrest Smithson, American athlete
• Gerald Smithson, English cricketer
• Jerred Smithson, former NHL player
• Moondog Spike, wrestler born Bill Smithson
• Rodney Smithson, footballer who played for Oxford United

• Alan Smithson, Bishop of Jarrow
• John Smithson (university president), American college administrator
• John Smithson, producer at the Discovery Channel
• Mike Smithson (disambiguation), several people

• Andrea Smithson Darling, a character on Dirty Sexy Money
• Charles Smithson, a major character in The French Lieutenant's Woman
• "Smithson", a webcomic by Shaenon K. Garrity

• Ben-Hadad (Syriac)^[1]
• Kovachevich, Kovačević, Kovalevich, Kovalenko (Slavic)

• Smithson (crater)
• Smithson Glacier
• Smithson, Indiana
• Smythson, a British company
• Smithson Valley High School
• Smithson–McCall Farm
• Smithson and McKay Brothers Blocks
• Mount Smithson, one of the Prince Olav Mountains