The Bettiah Christians (Hindustani/Bhojpuri: Béttiah Masīhī or Béttiah ʿĪsāʾī), also known as Betiawi Christians, are the northern Indian subcontinent's oldest Christian community, which emerged in the 18th century. The origins of the Bettiah Christian community lie in Champaran in what is now the Indian state of Bihar, in which the king of the Bettiah Raj, Maharaja Dhurup Singh, invited Roman Catholic missionaries of the Order of Friars Minor Capuchin to establish the Bettiah Christian Mission there.
Upper and middle-caste Hindus who converted to Christianity in the 18th and 19th centuries constitute the majority of the ethnoreligious community of Bettiah Christians, though it has incorporated those from former Muslim, Newar and scheduled caste heritage as well.