Västerås Cathedral is the seat of the Diocese of Västerås in the Province of Västmanland, Sweden. The church building is a five-tiered cathedral, with copper-covered roof as well as a west tower with side extensions and an obelisk-shaped, copper-clad spire. It is built in the Scandinavian Brick Gothic style.

The Diocese of Västerås is a diocese within the Church of Sweden. Its Episcopal see is located in Västerås at Västerås Cathedral. The diocese was first established in the 12th century as part of the Roman Catholic church, but was made part of the Church of Sweden as a result of the Protestant Reformation in Sweden.