Family name สุมัย (Sumai 
, สุมัย , Suemai 
) , all over the world, is a rare last name. The cognomen สุมัย is habitual in Trinidad and Tobago, where it is quite a rare surname, Estonia, where it is a rare surname, and Tanzania. Not in comparison with a country's population, it is commonest in Indonesia, Tanzania, and Nigeria. More prevalently, สุมัย is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sumai | Tanzania, Thailand, India, Indonesia, Malaysia |
| สุมัย, Sueamai | Thailand |
| Suemai | New Zealand, Thailand, United States |