Agios Kosmas (Greek: Άγιος Κοσμάς) is a village, a community and a municipal unit of the Grevena municipality. Before the 2011 local government reform it was an independent municipality. The municipality was established in 1997 with the name Kosmas o Aitolos (Κοσμάς ο Αιτωλός), which was changed to Agios Kosmas in 2004. The seat of the municipality was in Megaro. The 2011 census recorded 49 residents in the village, 75 residents in the community and 870 residents in the municipal unit. The community of Agios Kosmas covers an area of 9.496 km2 while the municipal unit covers an area of 115.087 km2. The village is named after the 18th-century saint Cosmas the Aetolian.