Owatonna () is a city in Steele County, Minnesota, United States. The population was 25,599 at the 2010 census. It is the county seat of Steele County. Owatonna is home to the Steele County Fairgrounds, which hosts the Steele County Free Fair in August.
Interstate 35 and U.S. Highways 14, and 218 are three of the main routes in the city.
Owatonna was first settled in 1853 around the Straight River. The community was named after the Straight River, which in the Dakota language is Wakpá Owóthaŋna. A popular, but apocryphal, story is that the town is named after "Princess Owatonna," the daughter of a local Native American chief who was supposedly healed by the magic waters of a nearby spring. The earliest the Owatonna area was settled was in 1854 and platted in September 1855, but it was incorporated as a town August 9, 1858, then as a city on February 23, 1865.
In 1856, Josef Karel Kaplan emigrated from the village of Dlouhá Třebová, southeast of Prague, Bohemia (now the Czech Republic), and selected a quarter section [160 acres (65 ha)] of land near the town of Owatonna. Kaplan described Owatonna as having just 50 small homes, but predicted 100 within a year, along with a railroad.