Monastery of Panagia Mavriotissa, Byzantine monastery in Kastoria, Greece

The Monastery of Panagia Mavriotissa stands on the eastern shore of the Kastoria lake peninsula, about 4 km from Kastoria and opposite Mavrochori. The present church has a main nave and a lower narthex under a pitched roof, with a chapel of St John the Theologian added later to the south wall. The complex also keeps the abbot's residence, cells, a bell tower and a guesthouse.

The monastery stands where the troops of the Byzantine commander George Palaiologos encircled the attacking Normans in 1083. Emperor Alexios I Komnenos (r. 1081–1118) is believed to have built it to commemorate that event. It was first named Mesonesiotissa, became Krepenitissa in the early 17th century, and took the name Mavriotissa from the village of Mavrovo (Mavrochori) in the mid-to-late 17th century.

The interior walls display frescoes from the late 12th and early 13th centuries, showing traditional Byzantine religious artistic techniques. These paintings reveal the spiritual values and artistic skill of the people who created them.

The monastery is located about 4 kilometers from Kastoria town center and can be reached on foot or by car. Its lakeside setting provides a calm environment for exploration.

The monastery was first called Mesonesiotissa, "in the middle of the island"; in the early 17th century it became Krepenitissa after the nearby village of Krepeni, and by the mid-to-late 17th century it took the name Mavriotissa from Mavrochori (Mavrovo). It was a major landowner in Krepeni.