Nias Regency is a regency in North Sumatra province, Indonesia; it lies on the east side of Nias Island. The regency originally covered the entire island, but was reduced to the northern half, with an area of 3,495.39 square kilometres, following the creation of the new regency of Nias Selatan on 25 February 2003. It was further reduced by the creation …Nias Regency is a regency in North Sumatra province, Indonesia; it lies on the east side of Nias Island. The regency originally covered the entire island, but was reduced to the northern half, with an area of 3,495.39 square kilometres, following the creation of the new regency of Nias Selatan on 25 February 2003. It was further reduced by the creation of the new regencies of North Nias and West Nias and the independent municipality of Gunungsitoli from other parts of Nias Regency on 29 October 2008. Since the separation of the new regencies and municipality, the reduced Regency now covers 853.44 km² of land in the eastern part of the island, and had a population of 131,377 at the 2010 Census and 146,672 at the 2020 Census; the official estimate as at mid 2023 was 146,895. Its seat is the town of Gido.