| Jurisdiction: | Diocese |
| Surat Thani | |
| Latin: | Diœcesis Suratthanensis |
| Local: | สังฆมณฑลสุราษฎร์ธานี |
| Country: |  Thailand |
| Province: | Bangkok |
| Metropolitan: | Bangkok |
| Area Km2: | 76,562 |
| Population: | 9,015,380 |
| Population As Of: | 2004 |
| Catholics: | 6,682 |
| Catholics Percent: | 0.1 |
| Denomination: | Catholic |
| Sui Iuris Church: | Latin Church |
| Rite: | Roman Rite |
| Established: | 26 June 1969 |
| Cathedral: | St.Raphael Cathedral, Surat Thani |
| Bishop: | Paul Trairong Multree |
| Bishop Title: | Bishop |
| Metro Archbishop: | Francis Xavier Kriengsak Kovitvanit |
| Suffragan: | for one --> |
| Archdeacon: | for one--> |
| Emeritus Bishops: | Joseph Prathan Sridarunsil |
| Website: | Official website |
| Map: | Thailand Diocese Surat Thani.png |
The Roman Catholic Diocese of Surat Thani (Diœcesis Suratthanensis, th|สังฆมณฑลสุราษฎร์ธานี) in southern Thailand was founded in 1969, when it was split off from the Diocese of Ratchaburi by the papal bull Qui Regno Christi. It is a suffragan diocese of the Archdiocese of Bangkok. The area of Surat Thani was evangelized by the Salesians of Don Bosco in the 1930s.
The diocese covers an area of 76,562 km2, covering all of the southern provinces of Thailand, including Prachuap Khiri Khan as its northernmost province. As of 2001, of its nine million citizens, 6,682 or 0.1% are members of the Catholic Church. The diocese is divided into 39 parishes, which are grouped by four regions.
The St.Raphael Cathedral (Thai: อาสนวิหารอัครเทวดาราฟาเอล) is in the town of Surat Thani at 9.15°N 99.3344°W. The church was built in 1962, and became a cathedral when the diocese was established in 1969.