The Roman Catholic Diocese of Quilon is a diocese of the Latin Catholic Church in the Indian city of Kollam, and under the Ecclesiastical Province of Trivandrum. The diocese, which covers an area of 1,950 km2. (753 square miles), and contains a population of 4,879,553 - 235,922 (4.8%) of which are Catholic. The history Latin catholic Church in Quilon begins with the erection of a diocese on 9 August 1329. This diocese was later suppressed. The present day Diocese of Quilon was established as a Apostolic Vicariate on 15 March 1853 by bifurcating the Apostolic Vicariate of Verapoly. It was elevated as a diocese on 1 September 1886.As of 18 April 2018, Paul Antony Mullassery is the bishop of the Diocese of Quilon.