Nunukan Regency is a regency located in the North Kalimantan Province of Indonesia. It was officially established on October 4, 1999, following its creation from the northern districts of Bulungan Regency.
The region covers an area of 14,247.50 square kilometers and shares international borders with the Malaysian states of Sabah to the north and Sarawak to the west. Internally, it borders Tana Tidung Regency and Malinau Regency to the south, as well as the coastal city of Tarakan to the east.
Demographic data indicates a growing population in the regency, which was recorded at 140,841 during the 2010 census and 199,090 in 2020. As of mid-2024, the official population estimate stands at approximately 227,460.