Warner is a town in Merrimack County, New Hampshire, United States. The population was 2,937 at the 2020 census. The town is home to Magdalen College of the Liberal Arts, Rollins State Park and Mount Kearsarge State Forest. The town's central village, where 453 people resided at the 2020 census, is defined as the Warner census-designated place and is located along New Hampshire Route 103 and the Warner River.