Holt County Courthouse in O'Neill, Nebraska; seen from the west. The Art Deco building was constructed in 1936, and is listed in the National Register of Historic Places. – Ammodramus, Public domain – Wikimedia Commons Holt County is located in Nebraska. About 10,127 people live here (as of 2020). Between 2010 and 2020, the population declined from 10,435 to 10,127. The area covers about 6,262.0 square kilometers. The region is divided into 8 Municipalities. The region was founded in 1876. The name originates from Joseph Holt (Union Army general) Holt County is county in Nebraska, United States. More information at www.co.holt.ne.us.