For almost 300 years the Roman Catholic diocese did not have a cathedral. In 1862 Cavan parish church was extended and it became the new cathedral of the diocese under Bishop James Browne. In 1938 construction of the present cathedral began, and was completed in 1942 under Bishop Patrick Lyons. W.H. Byrne & Son were the architects of the new cathedral, and the contractor was John Sisk & Son. The total build cost of the cathedral was £209,000.
The cathedral opened and dedicated to Saint Patrick and Saint Felim in 1942. The cathedral was consecrated in 1947. Six stained glass windows from the studios of Harry Clarke and were added to the cathedral in 1994.