Last name Koelsum (Koelsum 
) , globally, is a very rare cognomen. The last name Koelsum is habitual in South-eastern Asia, particularly Indonesia, where it is a very rare surname. More prevalently, Koelsum is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Koelsum | Indonesia, South Africa |
De, Vanker, Isaacs, Mohamed, Saville, Awaldien, Roberts, Heynes, Ryklief, Fortune, Abrahams, Canfield, Williams, Alexander, Hendricks, Ghansar, Wolmarans, Harris, Essack, Aziz, Peck, Sevis, Allie, Abdol, Abass, Emeran, Adams, Simons, Kimmie, Parker, Davids, Gamiet, Jacobs, White, and Ehrenreich