Warner is a town in Merrimack County, New Hampshire, United States. The population was 2,833 at the 2010 census. The town is home to Northeast Catholic College, Rollins State Park and Mount Kearsarge State Forest.The town's central settlement, where 444 people resided at the 2010 census, is defined as the Warner census-designated place, and is located along New Hampshire Route 103 and the Warner River. The town also includes the villages of Davisville, Lower Village, Melvin Mills, and Waterloo.