Last name 西伦 (Theron 
, Xilun 
, 西伦 ) , around the world, is a common family name. The last name 西伦 is habitual in Namibia, where it is quite a common surname, British Virgin Islands, and South Africa. Measured by absolute frequency, this name is the most popular in South Africa, France, and Namibia. Much less frequently, 西伦 is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Theron | Namibia, China, South Africa, United States, France |
| Xilun | China, United Kingdom, United States, Canada, Peru |
| 西伦 | China |
| Sillen | United Kingdom, Belgium, Malaysia, United States, Netherlands |