Kaviraj is a title of honor, which was given to poets, bards, singers attached to royal court in medieval India. In Hindi and many other Indian languages, like Gujarati, such persons are identified as Kavi. A many of them, were given honorary title of Kaviraj. The descendants of such persons also started using the surname, Kaviraj.
The surname is usually found in people of Gujarat, Rajasthan, etc. One of the community where this surname is often found is Charan, who took singing as profession. The other such community are Gadhvi, Barot.