Walnut Grove is a town in Etowah County, Alabama, United States. It is part of the Gadsden Metropolitan Statistical Area. At the 2010 census the population was 698. From 1880 until the 1960 U.S. Census, with the exclusion of 1890 when no figure was reported, Walnut Grove had the distinction of being the least populated community wholly within Etowah County. It lost that distinction in 1970 to newly incorporated Ridgeville which has held the title since.