Jefferson City, informally Jeff City, is the capital of the U.S. state of Missouri. It had a population of 43,228 at the 2020 census, ranking as the 15th most populous city in the state. It is also the county seat of Cole County and the principal city of the Jefferson City Metropolitan Statistical Area, the second-most-populous metropolitan area in Mid-Missouri and the fifth-largest in the state. Most of the city is in Cole County, with a small northern section extending into Callaway County. Jefferson City is named for Thomas Jefferson, the third President of the United States.

Missouri is a landlocked state in the Midwestern region of the United States. Ranking 21st in land area, it borders Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas to the south and Oklahoma, Kansas, and Nebraska to the west. In the south are the Ozarks, a forested highland, providing timber, minerals, and recreation. The Missouri River, after which the state is named, flows through the center and into the Mississippi River, which makes up the eastern border. With over six million residents, it is the 18th-most populous state of the country. The largest urban areas are St. Louis, Kansas City, Springfield, and Columbia; the capital is Jefferson City.