Family name เสนาจักร (Sanajak 
, เสนาจักร , Senajak 
) , globally, is a rare cognomen. The family name เสนาจักร is characteristic of Thailand, where it is a rare surname, Australia, where it is a very rare surname, and India, where it is an extremely rare surname. Very seldom, เสนาจักร is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sanajak | India, Thailand |
| เสนาจักร | Thailand |
| Senajak | Australia, Thailand |
| Senachak | United States, Thailand |