Family name Kuplais (Kuplais 
) , in all the world, is a rare cognomen. The family name Kuplais is habitual in Northern Europe, particularly Latvia, where it is quite a rare surname.
| VARIANT | COUNTRY |
|---|---|
| Kuplais | Latvia |
| jānis kuplais Latvian actor (1941-2015), LV (b. 1941) |
|