Thapa Kaji is a large social group of people of Jharra/Pure Chhettri caste (Kshatriya varna) in Nepal.

The surname originated during the Khas Kingdom in Karnali region during middle age-it referred to a position/post of a warrior.

It was a hereditary family title awarded to some famous Nepali Kshatriya castes like Thapa, Basnyat/Basnet, Pande, and Kunwar etc.

Majority of Thapas Chhetri speak the Nepali language as mother tongue.

Currently many of the Thapa Chhetri are found in Nepal, and parts of India i.e. Sikkim, Himachal, Assam as well as in Bhutan and Myanmar.