Perryville is a city in Perry County, Missouri, United States. The population was 8,555 at the 2020 United States census. Perryville is the county seat of Perry County. Perryville was selected the county seat of Perry County by Robert T. Brown, Joseph Tucker, and Thomas Riney, who had been appointed to select the seat of justice. In 1821, Bernard Layton deeded 51 acres to the commissioners in exchange for one town lot. Fifty-three of the 99 town lots were sold for $1,486.25, which was used to build the first courthouse. The current courthouse is the third such structure. It was built in 1904 at a cost of $30,000. Perryville and Perry County were named for Commodore Oliver Hazard Perry, Naval hero of the War of 1812.