George Synadenos Astras

George Synadenos Astras (fl. c. 1354 – 1365/6) was a Byzantine official and provincial governor.

In 1354, holding the title of megas stratopedarches, he was entrusted with the renovation of the Hagia Sophia. In 1355 he was named governor of Ainos in Thrace, remaining in the post until c. 1357. In 1360–1364 he was governor of the island of Lemnos, and then of Thessalonica, until his death from the plague sometime before August 1368.

He had estates on Lemnos, some of which were inherited by his son, Michael Synadenos Astras (died 1400), and others which were granted to the Athonite monasteries of Great Lavra, Vatopedi, and Dionysiou. He was related by marriage to Emperor John V Palaiologos, and he was a friend and correspondent of the scholar Demetrios Kydones.