Worth County is part of the Mason City, IA Micropolitan Statistical Area.

There were 3,534 housing units at an average density of 9 per square mile (3.5/km2).

The racial makeup of the county was 98.37% White, 0.28% Black or African American, 0.09% Native American, 0.14% Asian, 0.01% Pacific Islander, 0.42% from other races, and 0.70% from two or more races.

The population ranking of the following table is based on the 2020 census of Worth County.

[1] † county seat From its inaugural election in 1860 through 1928, Worth County backed the Republican candidate in every election with the exception of 1912, when former Republican Theodore Roosevelt won as the Progressive candidate.

From 1932 to 1980, the county was a bellwether, backing the nationwide winner in every election in that span except for 1960.

He improved on this in 2020, taking almost 62% of the vote and winning by a margin of victory of nearly 26%, the best performance by any candidate since Lyndon B. Johnson in 1964, the best performance by a Republican since Herbert Hoover in 1928, and the best margin of victory for any candidate since 1928 as well.