Cognomen Karthikarajan (Karthikarajan 
) , in the entire world, is an extremely rare family name. The surname Karthikarajan is habitual in Northern America, particularly the United States, where it is an extremely rare surname. Much more frequently, Karthikarajan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Karthikarajan | United States, India |