Last name 雷克斯 (Rex 
, Lex 
, Reks 
) , around the world, is a common family name. The cognomen 雷克斯 is characteristic of Greenland, where it is quite a common surname, Fiji, and Papua New Guinea, where it is quite a rare surname. In absolute terms, it is commonest in the United States, Germany, and Indonesia. More frequently, 雷克斯 is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Rex | Germany, Philippines, United States, Papua New Guinea, China |
| Lex | Germany, Philippines, United States, Democratic Republic of the Congo, China |
| Reks | Germany, Philippines, United States, Indonesia, Nigeria |
| 雷克斯 | China |