During the nineteenth century it was erected a prefecture based in Labuan, an island off the northwestern coast of Borneo.

In this first visit, he was able to find a suitable spot where the future mission station would be built.

Thomas Jackson bought five (5) acres of land on a hill in Sandakan, and the same year ordered Rev.

By October in the same year, there was a proper house, a hostel for boys to stay in, and a small church.

Sandakan was subject to frequent pirate raids, however, leading many of the people to flee into the interior for safety.

Pundleider thought two priests serving in Sandakan were too many given conditions, and left in February 1884 to open a mission station in Bundu, Kuala Penyu.

However, in November 1885, Jackson ordered him to depart, because “Sandakan unhealthy; a wind blowing across the bay; many Chinese sick, no good water in town; and Fr.

The White Sisters (the Franciscan Missionaries of St. Joseph) opened St. Mary's Convent on 5 November 1891.

After the year 1899, Sandakan was an established Mission with a presbytery, a boys’ school, a convent, and church.

In the same year, a great number of Catholic Filipino refugees fled to Sandakan because of the war in the Philippines.

The next several years in the history of the Mission and School in Sandakan followed much the same pattern of short tenureship of various priests.

Mulders arrived in Sandakan in 1952, and wasted no time in rebuilding both the primary and secondary school buildings.

This led to serious erosion, but after that problem was solved, St. Mary's Church was finally constructed, opened, and solemnly consecrated in 1961 by the Rt.

He organized evangelization talks to gather new  converts and started the RCIA (Rite of Christian Initiation of Adults) in 1985.

These became avenues to evangelize invited guests and also to serve as a platform for the many church groups and communities to work together in unity.

One of the most important liturgical events in the parish was the introduction of the Chinese-language Mass, which resulted in the growth of the Chinese Catholic Community.

Chi also initiated the Sunday School programme where children received their faith formation and preparation for their First Communion and Confirmation.

It was first initiated by the Light of Jesus Christ Covenant Community, a fraternity laypersons' ministry which was based in Sacred Heart Cathedral, Kota Kinabalu.

Arthur John, who acts as its current priest-in-charge as of 2022-2023, as a result of the diocese's most recent clergy reshuffle, since Fr.

Vincent Lee, a Jesuit from Singapore, to give spiritual formation and anointing to the parishioners at a Lenten/Intercessory Retreat in 2000 and a Holy Spirit Seminar in 2001.

He also showed great interest in the healing and deliverance ministry, and sent some parishioners to Kota Kinabalu to attend seminars.

Paul Lo's ordination, he was assigned by the then-Bishop John Lee to Sandakan as the second assistant priest.

This probability was more or less confirmed with the visit by the Apostolic Delegate in Malaysia, Archbishop Salvatore Pennachio, to the three main parishes on the East Coast.

The new diocese covers the entire East Coast of Sabah which comprises the parishes of St. Martin in Telupid, St. Dominic in Lahad Datu, Holy Trinity in Tawau, and St. Mary in Sandakan (along with its outstation parish churches such as St. Joseph's Pecky Valley, St. Mark's Mile 12 Labuk Road, St. Peter's Sungai Manila and St. Paul's Ulu Dusun including the Church of Our Lady of Fatima, Beluran, which hitherto today is the newest full parish of this diocese since 2015-16).

Simon continued his priestly duties at the cathedral as rector until his transfer to St. Dominic's Church in Lahad Datu in July 2008 (but now he is concurrently the present rector since 2022, albeit holding the office non-consecutively after a long gap of 15 years owing to the latest clergy reshuffle).

Two LCD projectors were installed in 2011 to facilitate the parishioners in the viewing of hymns, liturgical prayers and responses particularly that of the New Roman Missal, as well as witnessing the Rite of Baptism and other activities.

David Garaman (a longtime parishioner of St. Dominic's church cum seminarian who hailed from Tambunan, but was resident in Lahad Datu for he was born and bred there to emigrant parents from the said district in Sabah's interior division), who was ordained by the Rt.

On 24 May 2010, the Good Shepherd Sisters (RGS) established their mission in the Sandakan Diocese by setting up Seri Murni Crisis Centre.

The centre offers a safe haven and temporary shelter for about ten (10) women and girls in crisis situations.

In the diocese's fifth year, the Diocesan Pastoral and Worship Centre has been built on the former site of the old Boys’ School classroom block and it was blessed on 26 October 2012.