Tromsdalen Church or the Arctic Cathedral (Norwegian: Tromsdalen kirke, Ishavskatedralen) is a parish church of the Church of Norway in Tromsø Municipality in Troms og Finnmark county, Norway. It is located in the Tromsdalen valley on the east side of the city of Tromsø. It is the church for the Tromsøysund parish which is part of the Tromsø domprosti (arch-deanery) in the Diocese of Nord-Hålogaland. The modern concrete and metal church was built in a long church style in 1965 by the architect Jan Inge Hovig. The church seats about 600 people.
Formally, the church is named Tromsdalen Church or sometimes Tromsøysund Church (Norwegian: Tromsdalen kirke or Tromsøysund kirke). The church is commonly nicknamed the Ishavskatedralen which literally means "The Cathedral of the Arctic Sea" or simply the "Arctic Cathedral". Despite its nickname, it is a parish church and not, in fact, a cathedral as it is commonly called.
The church was designed by the architect Jan Inge Hovig and is built mainly of concrete. The main contractor for the construction was Ing. F. Selmer A/S Tromsø. Because of the church's distinct look and situation, it has been called "the opera house of Norway", likening it to the famous Sydney Opera House in Sydney, Australia. The church is one of the most notable churches in Tromsø due to its design, although Tromsø does have another church of interest, Tromsø Cathedral, which is noted for being the only wooden cathedral in Norway.
The groundbreaking of the church was 1 April 1964 and it was completed in 1965. The new church was consecrated on 19 November 1965 by the Bishop Monrad Norderval. The church is built out of cast-in-place aluminium-coated concrete panels.
In 1972, a glass mosaic was added to the eastern side, made by Victor Sparre. The church acquired an organ built by Grönlunds Orgelbyggeri in 2005, with three manuals, pedal, 42 stops, and 2940 pipes. It replaced the old opus nr. 12 organ delivered by Vestlandske Orgelverksted, Hareid, which had 22 voices and 124 keys.