Melissia (Greek: Μελίσσια) is a suburb in the northeastern part of the Athens agglomeration, Greece. Since the 2011 local government reform it is part of the municipality Penteli, of which it is the seat and a municipal unit. Melissia is situated at the southwestern foot of the Penteli mountains, 12 km northeast of Athens city centre. It is a green residential town.
It was part of the municipality of Marousi until 1946, when it became a separate community. It became a municipality in 1990. The population of Melissia was more than 22,000 at the 2011 census. It has six primary schools, two high schools (Greek "Gymnasium"), one lyceum and a modern municipal swimming-pool.