Surname สินธุ (Sintu 
, Sinthu 
, สินธุ ) , across the world, is quite a common cognomen. The family name สินธุ is habitual in Qatar, where it is quite a rare surname, Sri Lanka, and Guatemala. Measured by absolute frequency, it is the most numerous in India, Thailand, and Sri Lanka. More frequently, สินธุ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sintu | Bangladesh, South Africa, Thailand, India, Guatemala |
| Sinthu | South Africa, Thailand, India, Sri Lanka, Saudi Arabia |
| สินธุ | Thailand |
| Sindhav | Australia, United States, United Kingdom, India |