John Doukas Palaiologos (, 1225/1230 – 1274) was a Byzantine aristocrat, brother to Emperor Michael VIII Palaiologos (r. 1259–1282), who served as the commander-in-chief of the Byzantine army. He played a prominent part in his brother's military campaigns, most notably in the crucial victory at the Battle of Pelagonia, but also in repeated campaigns against Epirus and against the Turks in Asia Minor. He retired from active service after his defeat at Neopatras, and died shortly after.