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 | Russia, Belarus, Kazakhstan, Armenia, Lithuania |
| إسحاق | Egypt, Yemen, Sudan, Iraq, Algeria |
| Isaach | Nigeria, Spain, United States, South Africa, Brazil |