River in the south of the Isle of Man, flowing through Ballasalla and Castletown into Castletown Bay.

The Silverburn rises in the southern uplands and reaches the sea at Castletown. A.W. Moore listed it among the five largest streams on the Island, with the Sulby, Glass, Dhoo and Neb.

Rushen Abbey was built on its western bank close to Ballasalla. The river therefore ran through the centre of one of the principal medieval ecclesiastical estates on Mann. The abbey's position beside the water was recorded in nineteenth-century descriptions of the ruins.

At Ballasalla the river was crossed by the Crossag, or Monk's Bridge, considered by antiquaries to be the oldest surviving bridge on the Island and probably associated with the abbey.

Further downstream the Silverburn passes Castle Rushen and enters Castletown harbour. The river and harbour shaped the position of both the castle and the town. One nineteenth-century account noted that at low water boats could be drawn up on the river banks while Castletown Bay provided shelter beyond.

The river thus connected Rushen Abbey, Ballasalla, Castle Rushen and the harbour within a short distance.