Ketapang diocese covers 35,300 square kilometers and includes the district of Ketapang in West Kalimantan province.
The Church of Ketapang had started in Ketapang in the year 1910. On July 1, 1950, Capuchin Archbishop Herkulanus van Valenberg of Pontianak established Ketapang as a mission area and asked the Congregation of the Passion of "Mater Sanctae Spei" of the Netherlands to serve here. Passionist Father Raphael Kleyne worked here from July 1, 1950 to Feb. 27, 1952, when he died in a motorboat accident. Passionist Father Gabriel Sillekens replaced him in 1953 as delegate vicar.
On June 26, 1954, Pope Pius XII increased the status of Ketapang from mission area to be Apostolic Prefecture with Passionist Father Gabriel Wilhelmus Sillkens as the first its first apostolic prefect.
In January 1961, Pope John Paul XXIII established the Catholic hierarchy in Indonesia. Ketapang was declared a diocese on Jan. 3, 1961 and Father Sillkens was appointed the first bishop. He was consecrated a bishop in 1962.
About 60 percent of the inhabitants of Ketapang district are Muslim Malay, 30 percent are from the native tribe of Daya-Klemantan. The others are Arabians, Chinese, Javanese, Maduranese, Bataknese, Florinese and Bugisnese.
The first Catholics were five Chinese families from Swatow, China, who were first visited by a priest in 1911. The Passionists came to Ketapang in 1947 to minister to 600 Catholics formerly served by the Capuchins.