Family name Isaach (Исаак 
, إسحاق 
, Isaach 
) , globally, is a rare last name. The last name Isaach is habitual in Armenia, where it is quite a common surname, Kyrgyzstan, where it is a rare surname, and Yemen. In absolute terms, it is the most numerous in Armenia, Yemen, and Russia. More prevalently, Isaach is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Исаак | Kazakhstan, Armenia, Russia, Belarus, Lithuania |
| إسحاق | Yemen, Sudan, Algeria, Egypt, Iraq |
| Isaach | South Africa, Spain, Nigeria, United States, Brazil |