Niels (c. 1065 – 25 June 1134) is King of Denmark from 1104 to 1134.

Niels precedes his brother Eric Evergood and is presumed to have been the youngest son of King Sweyn II Estridson.

King Niels actively supports the canonization of Canute IV the Holy and supports his son Magnus I of Sweden by killing the potential successor Knud Lavard.

His secular rule wis supported by the clergy.

Niels is killed in an ensuing civil war, and is succeeded by Eric II Emune.