The present population of Sikkim is composed of different races and ethnic groups, viz., the Lepchas, the Bhutias, the Nepali language speaking Indian Gorkhas and the Plainsmen, who came and settled in different phases of history.

The Anthropological Survey of India has identified 21 communities in Sikkim and more than 13 different languages belonging to different linguistic stock are spoken in the state.

While the Report of the Commission for Review of Environmental and Social Sector, Policies, Plans and Programmes (CRESP, 2008) records different communities and tribes of Sikkim such as Bhujel, Bhutia, Bahun (Khas), Chhetri (Khas), Yakkha, Damai, Gurung, Kami, Rai, Lepcha, Limbu, Magars, Newar, Jogi (Sanyasi/Giri), Sarki, Sherpa, Sunuwar, Tamang, and Thami.

Additional official languages include Gurung, Limbu, Magar, Sunuwar, Newar, Rai, Sherpa and Tamang for the purpose of preservation of culture and tradition in the state.

Hindu and Buddhist both celebrates Local Festivals : Dashain (Vijaya Dashami), Tihar (Dipawali), Losar, Saga Dawa, Sakewa, Tendong Lho Rumfaat, Losoong/Namsoong, Indra Jatra, Sonam Lhosar, Tamu Lhosar, Chasok Tangnam, Maghe Sankranti, Buddha Jayanti, Rama Navami, Pang-Lhabsol, Lhabab Duechen.

Teyongsi Srijunga Sawan Tongnam, Barahimizong, Kagyed Dance, Guru Rimpoche's Thunkar Tshechu, Bhanu Jayanti etc.

Christians in Sikkim are mostly descendants of Lepcha people who were converted by British missionaries in the late 19th century and constitute around 10 per cent of the population.