Chaudandigadhi is a municipality in Udayapur District of Province No. 1 in Nepal that was established on 10 March 2017 by merging the former Village development committees Chaudandi, Siddipur, Hadiya and Sundarpur with the former municipality Beltar Basaha. At the time of the 2011 Nepal census, the localities out of which Chaudandigadhi would be formed had a joint population of 48,574 people living in 10,519 individual households. It is surrounded by Belka Municipality in the east, Triyuga in the west, the districts of Khotang and Bhojpur in the north and Sunsari District in the south.