| Jurisdiction: | Diocese |
| Sanyuan | |
| Latin: | Dioecesis Saniüenensis |
| Country: | China |
| Metropolitan: | Xi’an |
| Province: | Xi’an |
| Rite: | Latin Rite |
| Cathedral: | Cathedral of the Sacred Heart of Jesus in Sanyuan, Xianyang |
| Area Km2: | 12,600 |
| Population: | 4,830,000 |
| Population As Of: | 2010 |
| Catholics: | 40,000 |
| Catholics Percent: | 0.82 |
| Bishop: | Joseph Han Yingjin |
| Metro Archbishop: | Anthony Dang Mingyan |
The Roman Catholic Diocese of Sanyuan (Latin: Saniüenen(sis),) is a diocese located in Sanyuan in the ecclesiastical province of Xi'an, and is centered in the Chinese province of Shaanxi.