Bihari is a demonym given to the inhabitants of the Indian state of Bihar. Bihari people can be separated into three main Indo-Aryan ethnolinguistic groups, Bhojpuris, Maithils and Magadhis. They are also further divided into a variety of hereditary caste groups. In Bihar today, the Bihari identity is seen as secondary to caste/clan, linguistic and religious identity but nonetheless is a subset of the larger Indian identity. Biharis can be found throughout India, and in the neighbouring countries of Nepal, Pakistan and Bangladesh. During the Partition of India in 1947, many Bihari Muslims migrated to East Bengal. Bihari people are also well represented in the Muhajir people of Pakistan because of Partition.

Bihar is a state in Eastern India. It is the third largest state by population, the 12th largest by area, and the 14th largest by GDP in 2021. Bihar borders Uttar Pradesh to its west, Nepal to the north, the northern part of West Bengal to the east, and Jharkhand to the south. Bihar is split by the river Ganges, which flows from west to east. On 15 November 2000, southern Bihar was ceded to form the new state of Jharkhand. Only 11.27% of the population of Bihar lives in urban areas as per a 2020 report. Additionally, almost 58% of Biharis are below the age of 25, giving Bihar the highest proportion of young people of any Indian state. The official language is Hindi, which shares official status alongside that of Urdu. The main native languages are Maithili, Magahi and Bhojpuri. But there are several other languages being spoken at smaller levels.