The term Serb Muslims (Serbian: Срби муслимани/Srbi muslimani) refers to ethnic Serbs who are Muslims (adherents of Islam) by their religious affiliation. Since it is defined by ethnicity and religion, term Serb Muslims should not be confused with term Serbian Muslims that refers generally to all adherents of Islam in Serbia, regardless of their ethnicity.
The term has several particular uses:
Since Serbs were, and still are, predominantly Eastern Orthodox Christians, their first significant historical encounter with Islam occurred in the second half of 14th century, and was marked by Turkish invasion and conquest of Serbian lands (starting in 1371 and ending by the beginning of 16th century). That interval was marked by first wave of Islamization among Serbs: in some regions, substantial minority left Christianity and converted into Islam, willingly or by necessity, under the influence of Ottoman authorities. The most notable Muslim of Serb ethnicity was Mehmed-paša Sokolović (1506-1579), Grand Vizier of the Ottoman Empire (1565-1579), who was ethnic Serb by birth.
Gajret (known as Serbian Muslim Cultural Society after 1929) was a cultural society established in 1903 that promoted Serbian identity among the Slavic Muslims of Austria-Hungary (today's Bosnia and Herzegovina). The organization viewed that the Muslims were Serbs lacking ethnic consciousness. The view that Muslims were Serbs is probably the oldest of three ethnic theories among the Bosnian Muslims themselves. It was dismantled by the Independent State of Croatia during World War II. Some members, non-Communists, joined or collaborated with the Yugoslav Partisans, while others joined the Chetniks.