Sint-Gertrudiskathedraal (St. Gertrude's Cathedral), Utrecht

Sint-Gertrudiskathedraal (St. Gertrude's Cathedral) in Utrecht is the seat of local Archbishop and the mother church of the Old Catholic Church of the Netherlands.

The current building was constructed between 1912 and 1914, designed by E.G. Wentinck in Neo-Romanesque style, echoing St. Mary's Church, which formerly stood very close by, on Mariaplaats. Its predecessor, called St. Gertrude's Chapel (Dutch: Gertrudiskapel), has been preserved, and is currently attached to the Cathedral. The chapel was built in 1634, as part of a medieval house, and was used as a clandestine temple for the members of the Roman Catholic parish of the Geertekerk (original St. Gertrude's Church which is now in the possession of the Remonstrants).

In the Old Catholic Schism in 1723, the parish joined the Old Catholic Church, as well as James Parish and the Parish of Maria Minor. Subsequently, Gertrude's Chapel was elevated to the status of cathedral church of the Old Catholics.

The once hidden church is one of the best-preserved architectural monuments in the Netherlands. Its current appearance was mainly achieved during renovation in 1697, during which the house floors were broken through to create galleries. Most recently, from 1991 to 1993, the church had once again undergone restoration.

In the altar there are more than 1700 relics held in hundreds of containers. Among them is said to be a fragment of the rib of St. Willibrord.