Digboi (IPA: ˈdɪgˌbɔɪ) (Assamese: ডিগবৈ) is a town and a town area committee in Tinsukia district in the north-eastern part of the state of Assam, IndiaCrude oil was discovered here in late 19th century. Digboi is known as the Oil City of Assam where the first oil well in Asia was drilled. The first refinery was started here as early as 1901. Digboi has the oldest oil well in operation.