Osman III or Othman IIIText not available (Ottoman Turkish: عثمان ثالث ‘Osmān-i sālis) (January 2/3, 1699 January 30/October 30, 1757) was the Sultan of the Ottoman Empire from 1754 to 1757.
The younger brother of Mahmud I (1730–54) and son of Mustafa II (1695–1703) and Valide Sultan Saliha Sabkati, born at Edirne Palace, Osman III was a generally insignificant prince. His brief reign is notable for a rising intolerance of non-Muslims (Christians and Jews being required to wear distinctive clothes or badges) and for a fire in Istanbul. His mother was Şehsuvar Sultan, a Serbian valide sultan.
thumb|left|Audience of French ambassador Charles de Vergennes with Sultan Osman III in 1755.
Osman III lived most of his life as a prisoner in the Palace, and so upon becoming Sultan he had some behavioral peculiarities. Unlike previous Sultans, he hated music, and sent all musicians out of the palace. Also living in the "kafes", the palace prison in the "harem" which was the part of the palace containing women's quarters, he grew a dislike for women's companionship. Therefore he would wear iron shoes in order to not cross paths with any women, and by wearing such shoes they could hear him approach and disperse. He died at Topkapi Palace, Istanbul. He married Layla, without issue.