Ian Stewart
Ian Stewart may refer to:
Military
- Ian Stewart (RAF officer), current United Kingdom National Military Representative, Supreme Headquarters Allied Powers Europe
 - Ian MacAlister Stewart (1895–1987), brigadier general during the Second World War
 - Ian Michael Stewart, former senior commander in the Royal Air Force
 
Politics
- Ian Stewart (Labour politician) (born 1950), Scottish politician
 - Ian Stewart, Baron Stewartby (1935–2018), British Conservative Party politician and former MP for Hitchin, England
 
Sports
- Ian Stewart (athlete) (born 1949), Scottish Olympic athlete
 - Ian Stewart (Australian rules footballer) (born 1943), member of the Australian Football Hall of Fame
 - Ian Stewart (baseball) (born 1985), major league baseball player
 - Ian Stewart (Northern Ireland footballer) (born 1961), member of the 1986 Northern Ireland Football World Cup team
 - Ian Stewart (racing driver) (1929–2017), Scottish Formula One driver
 - Ian Stewart (Scottish footballer) (born 1945/46), Scottish football player and manager
 
Others
- Ian Stewart (mathematician) (born 1945), English academic and science fiction author
 - Ian Stewart (musician) (1938–1985), British musician and early member of the Rolling Stones
 - Ian Stewart (police commissioner), former Commissioner of the Queensland Police Service (2012–2019)
 - Ian Stewart, founder of Gremlin Interactive and Zoo Digital
 - Ian Stewart (priest) (born 1943), Dean of Brechin
 - Ian Charles Stewart (born 1958), entrepreneur and co-founder of Wired magazine
 - Ian Duncan Stewart (1938–2017), or Ian Brady, British serial killer and author
 - Ian Edward Stewart (1908–1989), English pianist and bandleader, Savoy Orpheans