David Megas Komnenos (; – 1 November 1463) was the last Emperor of Trebizond from 1459 to 1461. He was the third son of Emperor Alexios IV of Trebizond and Theodora Kantakouzene. Following the fall of Trebizond to the Ottoman Empire, he was taken captive with his family to the Ottoman capital, Constantinople, where he and his sons and nephew were executed in 1463.