Bulungan Regency is a regency of North Kalimantan Province in Indonesia. It covers an area of 13,181.92 km² and had a population of 112,663 at the 2010 Census^[2] and 151,844 at the 2020 Census;^[3] the official estimate as at mid 2022 was 157,593 (comprising 84,071 males and 73,522 females).^[1] The administrative centre is at Tanjung Selor.

The Bulangan Regency was originally co-extensive with what subsequently became the province of North Kalimantan. On 8 October 1997 the town of Tarakan was cut out of the regency to become an independent city. Two years later, on 4 October 1999, the remaining territory of the regency was split to create two additional regencies - Malinau Regency and Nunukan Regency. On 17 July 2007, three more districts (kecamatan) was split from Bulungan Regency to form a new regency, Tana Tidung Regency.^[4]

Bulangan Regency had originally been part of the East Kalimantan province, but in 2012 it - together with the areas carved out of it in 1997, 1999 and 2007 - became part of the newly created North Kalimantan province. Tanjung Selor in Bulungan Regency was designated as the province's capital.^[5]

The regency is divided into ten districts (kecamatan), tabulated below with their areas and their populations at the 2010 Census^[2] and the 2020 Census,^[3] together with the official estimates as at mid 2022.^[1] The table also includes the locations of the district administrative centres, the number of administrative villages in each district (a total of 74 rural desa and 7 urban kelurahan), and its postal codes.

Notes: (a) including 5 offshore islands.
(b) comprising 4 kelurahan (Karang Anyar, Tanjung Palas Hilir, Tanjung Palas Hulu and Tanjung Palas Tengah) and 5 desa. (c) including 7 offshore islands.
(d) comprising 3 kelurahan (Tanjung Selor Hilir, Tanjung Selor Hulu and Tanjung Selor Timur) and 6 desa. (e) including 65 offshore islands. (f) including 10 offshore islands.

• Sultanate of Bulungan