The Ottoman Interregnum, or the Ottoman Civil War, was a civil war in the Ottoman Empire between the sons of Sultan Bayezid I following their father's defeat at the hands of Timur in the Battle of Ankara on 20 July 1402. Although Timur confirmed Mehmed Çelebi as sultan, Mehmed's brothers İsa Çelebi, Musa Çelebi, Süleyman Çelebi, and later, Mustafa Çelebi, refused to recognize his authority, each claiming the throne for himself. This resulted in civil war. The Interregnum would last a little under 11 years, culminating in the Battle of Çamurlu on 5 July 1413, when Mehmed Çelebi emerged as victor, crowned himself Sultan Mehmed I, and restored the empire.

Süleyman Çelebi was an Ottoman prince and a co-ruler of the Ottoman Empire for several years during the Ottoman Interregnum. There is a tradition of western origin, according to which Suleiman the Magnificent was "Suleiman II", but that tradition has been based on an erroneous assumption that Süleyman Çelebi was to be recognised as a legitimate sultan.