Ivan III (disambiguation)
Ivan III may refer to:

Ivan III Nelipac (died 1434), viceroy of Croatia 
Ivan III of Russia (1440–1505), grand prince of Moscow and later sovereign of all Russia
Ivan III of Ryazan, grand prince of Ryazan (1427–1456)
Ivan III Draskovic (1595 or 1603 – 1648), Croato-Hungarian warrior and statesman, Palatine of Hungary 
Ivan Asen III of Bulgaria, tsar of Bulgaria 1279–1280