Manly is a city in Worth County, Iowa, United States, whose population was 1,256 at the time of the 2020 census. It is part of the Mason City Micropolitan Statistical Area.

Worth County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 7,443. The county seat is Northwood. The county was founded in 1851 and named for Major General William Jenkins Worth (1794–1849), an officer in both the Seminole War and the Mexican–American War.