The Diocese of Reykjavík (Latin: Dioecesis Reykiavikensis) is a Latin Church diocese of the Catholic Church which covers the whole of the country of Iceland, and numbered 14,723 Catholics as of 2022.

In 2015 the then bishop, Pierre Bürcher retired and Father Dávid Bartimej Tencer, OFM Cap., was appointed to succeed him as the fifth bishop of the diocese.

Patrick Breen, rector of Landakot Cathedral, Christ the King Parish.

The medieval church was represented by the sees of Skálholt (created 1056) and Hólar (1106), but these became Lutheran during the Reformation.

Iceland remained without Roman Catholic prelates until the Apostolic Prefecture was established at Reykjavík in 1923.