The Nidaros Cathedral Boys' Choir (Chorus Puerorum Cathedralis Nidrosiensis) is a Norwegian choir in Trondheim, consisting of 76 boys and men as of spring 2008.
At the end of the 11th century Norwegian and English stone carvers came to Trondheim to build the Christ Church, the predecessor to the cathedral.
In one of the chapels the stonecarvers' sons were instructed by the clergymen in Gregorian chant and liturgy, and the boys sang at masses, just like today's choir.
But when planning the 900th anniversary of the death of St. Olav, chaplain Arne Fjellbu, later to become bishop, took the initiative to establish a new boys' choir in Trondheim.
In the autumn of 1927 Nidaros Cathedral Boys' Choir was re-established under the leadership of conductor Erik Saltnessand.