Family name Derw (Derw 
) , around the world, is a rare last name. The cognomen Derw is habitual in Southern Asia, particularly India, where it is an extremely rare surname. Very seldom, Derw is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Derw | United States, India, Thailand |
| hywel melyn ap gwilym gam ap hywel fychan ap hywel of ynys derw |
|