Manuel II Palaeologus (1350 – July 21 1425) was Byzantine emperor from 1391 to 1425, and son of Emperor John V Palaeologus. By Helena Dragas , the daughter of a Serbian prince, he had seven sons: Michael (died 1406), John, Theodore, Andronikos, Constantine, Demetrius, and Thomas.

At the time of his father's death he was a hostage at the court of the Ottoman emperor Beyazid I at Brusa (modern Bursa), but succeeded in making his escape; he was forthwith besieged in Constantinople by the sultan, whose victory over the Christians at the Battle of Nicopolis, however (September 25, 1396), did not secure for him the capital.

Manuel subsequently set out in person to seek help from the West, and for this purpose visited Italy, France, Germany and England, but without material success; the victory of Timur at the Battle of Ankara in 1402, and the death of Beyazid in 1403 were the first events to give him a genuine respite from Ottoman oppression. He stood on friendly terms with Mehmed I, but was again besieged in his capital by Murad II, in 1422. Shortly before his death he was forced to sign an agreement whereby the Byzantine Empire undertook to pay tribute to the sultan.

Manuel was the author of numerous works of varied character — theological, rhetorical, poetical and letters.