The Islamic Crescent is a symbol consisting of a crescent with a star at the concave side. In its modern form, the star is usually shown with five points (though in earlier centuries a higher number of points was often used). The two signs together, or the crescent only, was long a symbol of Byzantium and also appeared on coins of the Sassanid Empire. Now it is often a symbol of Islam. It is seen on a number of different country flags such as Turkey, Libya, Maldives, Algeria, Azerbaijan, Malaysia, Singapore, Turkmenistan, Uzbekistan, Tunisia, Western Sahara, Comoros, North Cyprus, Mauritania, Pakistan^{[n 1]} respectively.

Flag of Ottoman Empire was the first flag featuring a crescent with a star. Other states formerly part of the Ottoman Empire also used the symbol, so the symbol emerged into popular use.