Koca Mehmed Husrev Pasha (sometimes in earlier writings rendered as Khosref pasha or Hoshref pasha) (1769–1855) was an Ottoman admiral and statesman who reached the top position of Grand Vizier rather late in his career, between 2 July 1839 and 8 June 1840 during the reign of Abdülmecid, but who occupied key administrative roles in three different aspects, namely the fight against regional warlords, the reformation of the army and the attire, in the Ottoman Empire in the 1820s.
During the Greek War of Independence he held the rank of Kaptan Pasha (the Grand Admiral) of the Ottoman Navy. In this role he captured and destroyed the island of Psara on June 21, 1824, and then moved against Samos, where he was joined by the Egyptian fleet under Ibrahim Pasha. During the months of July and August, several skirmishes and constant maneuvers followed between the Ottoman and Greek fleets, culminating in the Naval Battle of Gerontas, which resulted in a Greek victory.
After his dismissal from the leadership of the Navy, he was appointed Governor of the Vilayet of Trabzon twice, during which time he conducted for the Black Sea region of Turkey the struggle the central Ottoman state was waging against local feudal rulers.
Having gained the confidence of Sultan Mahmud II, Kodja Mehmed Hüsrev Pasha then played vital roles both in the annihilation of the Janissary Corps in 1826, and in the formation of a new Ottoman Army (the Mansure Army) modeled after those of European Powers.
Kodja Mehmed Hüsrev Pasha was also instrumental for the near-abandon of the turban and the adoption of the fez as a universal headgear for Muslim men of the Ottoman Empire (excluding the religious classes). He had seen the fez as worn occasionally by Tunisians and Algerians during a Mediterranean journey and introduced it to the Ottoman capital, from where it the custom -encouraged by the authorities- spread to all Ottoman lands including the nominal dependency of Egypt.