Nikolsburg is the name of several Hasidic dynasties, named for rabbinic leaders of the town of Nikolsburg (Mikulov) in Moravia.
There currently exist three distinct Hasidic communities named Nikolsburg:
The largest of these is that of Monsey.
The term Nikolsburger Rebbe can refer either to the historic Rebbe Shmelke of Nikolsburg, or to the leader of any of the three current Nikolsburg dynasties above.
The community of the Nikolsburg dynasty in Monsey has a yeshiva for young adults and boys, a Kollel and a Beis Midrash (Study hall).