Cerro Gordo County was organized in 1855 and Mason City was picked as the first county seat. In 1856, the Iowa legislature appointed three commissioners to chose a new location for the county seat. They picked a site called Livonia, near the village of Clear Lake. In 1857, over half the citizens of the county signed a petition to move the county seat back to Mason City. The county seat returned to Mason City in 1858. Although a courthouse was built in Livonia, nothing is left standing to recall the once-promising city.
Mason City's first courthouse stood on the site where a theater is now located. It was soon outgrown and board of supervisors tried to get a new one in 1880. But the plan was not approved until 1899. A $64,000 courthouse was then constructed.
In the late 50's concern over the security of county records led the county to expand. The Standard Oil Building in Mason City was purchased for $159,400 and remodeled. The courthouse was ready for service by 1960 and is 30,000 square feet larger than the previous courthouse. It continues to serve Cerro Gordo today.