Orhan or Orhan Bey (1281 – March 1362) is the second bey of the nascent Ottoman Empire (at this time known as the Ottoman Beylik or Emirate) from 1326 to 1362.

He was born in Söğüt, the son of Osman I and Malhun Hatun.

In the early stages of his reign, Orhan focuses his energies on conquering most of northwestern Anatolia.

The majority of these areas are under Byzantine rule and he wins his first battle, at Pelekanon, against the Byzantine Emperor Andronikos III Palaiologos.

Orhan also occupies the lands of the Karasids of Balıkesir and the Ahis of Ankara.

A series of civil wars surrounding the ascension of the nine-year-old emperor John V Palaiologos benefits Orhan greatly.

In the Byzantine civil war of 1341–1347, the regent John VI Kantakouzenos marries his daughter Theodora to Orhan and employs Ottoman warriors against the rival forces of the queen dowager, allowing them to loot Thrace.

In the Byzantine civil war of 1352–1357, Kantakouzenos uses Ottoman forces against John V himself, granting them the use of a European fortress at Çimpe around 1352.

A major earthquake devastates Gallipoli (modern Gelibolu) two years later and Orhan's son Süleyman Pasha occupies the town, giving the Ottomans a strong bridgehead into mainland Europe.