The Mosfell Church belongs to the Mosfell benefice in the Arnes deanery.  The present, wooden church was built in 1848.  Carpenter Bjarni Jonsson was responsible for the construction.  The church has been maintained and reconstructed and was re-consecrated on the 15^th of July 1979.  Carpenter Asmundur Jonsson of Langholt made the pulpit and the works of Ofeigur Jonsson of Heidarbaer in the Thingvellir County also decorate the church.

Catholic churches at Mosfell were dedicated to Holy Mary.  Annexed churches are in Middalur, at Stora Borg, Burfell and Lake Ulfljotsvatn.  In the early 20^th century the benefices of Mosfell, Burfell and Klausturholar were to be abolished and united with a new church at Stora Borg.  It was built and only the Klausturholar benefice was abolished and united with the Stora Borg benefice.