Burg Rittersdorf, Medieval fortress in Rittersdorf, Germany.

Burg Rittersdorf is a moated castle on the Nims in Rittersdorf, its near-square complex enclosed by a water-filled ditch. On the east side stands the round bergfried, 26 metres high, with a residential tower from around 1300 on the north side. A dwelling built from 1550 and a gate bearing the coat of arms dated 1575 complete the ensemble.

Burg Rittersdorf was first documented in 1263, probably built by Theoderich von Rittersdorf, likely as under-advocate of the Counts of Luxembourg for the Abbey of St. Maximin in Trier, to secure the Trier–Bitburg–Prüm–Cologne road. In 1290 King Rudolf of Habsburg permitted a bergfried. From the 15th century the lords of Enschringen held the fief and from 1550 built a residential building with two round towers. The lordship stayed with the Duchy of Luxembourg until the late 18th century.

The castle's name comes from the lords of Rittersdorf, and the lordship it anchored covered the villages of Rittersdorf and Nattenheim. Since renovation between 1978 and 1987 the complex has housed a local history museum and a registry office wedding room, so civil marriages take place inside the old walls.

The fortress is open year-round and houses a restaurant with local food along with a small museum. Visitors should wear sturdy shoes since pathways and stairs in the old buildings are uneven.

The 26-metre round bergfried on the east side was authorised in 1290 by King Rudolf of Habsburg; a residential tower from around 1300 stands on the north side, and the gate with coats of arms dates from 1575. The complex was extensively restored between 1978 and 1987.