Stephen III, commonly known as Stephen the Great ; died on 2 July 1504), was Voivode of Moldavia from 1457 to 1504. He was the son of and co-ruler with Bogdan II, who was murdered in 1451 in a conspiracy organized by his brother and Stephen's uncle Peter III Aaron, who took the throne. Stephen fled to Hungary, and later to Wallachia; with the support of Vlad III Țepeș, Voivode of Wallachia, he returned to Moldavia, forcing Aaron to seek refuge in Poland in the summer of 1457. Teoctist I, Metropolitan of Moldavia, anointed Stephen prince. He attacked Poland and prevented Casimir IV Jagiellon, King of Poland, from supporting Peter Aaron, but eventually acknowledged Casimir's suzerainty in 1459.

Moldavia is a historical region and former principality in Central and Eastern Europe, corresponding to the territory between the Eastern Carpathians and the Dniester River. An initially independent and later autonomous state, it existed from the 14th century to 1859, when it united with Wallachia as the basis of the modern Romanian state; at various times, Moldavia included the regions of Bessarabia, all of Bukovina and Hertsa. The region of Pokuttya was also part of it for a period of time.