Manasija Monastery is a 15th-century Serbian Orthodox monastery located near the town of Despotovac in central Serbia. The monastery was founded by the Serbian medieval ruler Despot Stefan Lazarević in the early 1400s.

The massive structure was dedicated to the Holy Trinity and belongs to the Morava architectural style. The monastery complex is surrounded by monumental, mostly rectangular walls used for defense. The walls consisted of 11 towers, with the most prominent being the Despot's tower.

During the early 21st century, a team of archaeologists found the remains of a person believed to be Despot Stefan Lazarević. DNA analysis confirmed that the remains belonged to a son of Tsar Lazar, Stefan's father, one of the most prominent Serbian rulers during the Middle Ages. However, it could have been Lazarević's brother, Vuk, who was also buried at the monastery. 

The monastery was also home to the medieval Resava School Of Transcription, a center for transcribing, translating, and illuminating manuscripts in the Serbian despotate. It was established by Lazarević in 1407. The monastery contained a library of more than 20,000 books, and the canon of this school was followed in a number of monasteries across the Balkans. 

Since 2015, the monastery and its picturesque surroundings have become the venue for the "Just Out"  festival. The event is held each year at the end of August and hosts knights from over 20 countries. Visitors enjoy medieval music concerts, traditional culinary specialties, and spectacular battle tournaments featuring knights underneath the massive fortifications of the monastery.