It was elevated on 21 March 1977, also by Pope Paul VI to Diocese of Jeju 제주 / Cheju / 濟州 (正體中文) / Cheiuen(sis) (Latin).[1]
Statistics
As per 2014, it pastorally served 71,845 Catholics (11.9% of 604,670 total) on 1,849 km2 in 27 parishes with 51 priests (44 diocesan, 7 religious), 1 deacon, 110 lay religious (7 brothers, 103 sisters) and 17 seminarians.