The Puroik language (previously called Sulung, a derogatory term, by other tribes) is a set of language varieties spoken by the Puroik people of Arunachal Pradesh in India and of Lhünzê County, Tibet, in China.

Besides their own language, the Puroik also use Nishi, Hindi, and Assamese. Literacy is very low, at about 2%. Those who are literate use either the Bengali-Assamese script, Devanagari or the Latin alphabet to write Puroik.

Remsangpuia (2008:17) listed a limited number of Puroik villages. Currently, Puroik are seen inhabiting the following districts and circles of Arunachal Pradesh. They also live in Nyishi, Aka, and Miji areas.

According to the Ethnologue, Puroik is spoken in 53 villages along the Par River in Arunachal Pradesh.

The Puroik are located from the Upper Subansiri River drainage basin (西巴霞区) to the Tawang River drainage basin (Li 2005). Names include pɯh˧˩ ɣut˥ (autonym) and su˥ loŋ˧ (Bangni exonym). There are about 3,000 Puroik as of 2002, who are classified as ethnic Lhoba by the Chinese government.

Lieberherr (2015) consider Puroik to be a dialect chain where geographically distant dialects are mutually unintelligible, whereas dialects located close to each other are mutually intelligible. The internal diversity of Puroik is about equal to that of the Western Kho-Bwa branch. Lieberherr (2015) and Lieberherr & Bodt (2017) list the following dialects of Puroik, provided here in geographical order from east to west.

Lieberherr & Bodt (2017) classify Puroik as Kho-Bwa, and has traditionally been considered to be a Sino-Tibetan language. There is some mutual intelligibility with Bugun, and Burling (2003) grouped it with Bugun and Sherdukpen, and possibly with Lish and Sartang.

James A. Matisoff (2009) considers Puroik to be a Tibeto-Burman language that has undergone sound changes such as: