Last name Вячслав (Вячслав 
, Viachslav 
, Vyachslav 
) , in all the world, is a very rare surname. The cognomen Вячслав is characteristic of Kyrgyzstan, where it is a very rare surname, and China, where it is an extremely rare surname. More prevalently, Вячслав is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Вячслав | Russia, Ukraine, Kazakhstan, Kyrgyzstan |
| Viachslav | Russia, United States, China |
| Vyachslav | Canada, United States |
| Viatchslav | United States |