Kirkwood is an inner-ring suburb of St. Louis located in western St. Louis County, Missouri. As of the 2020 census, the city's population was 29…Kirkwood is an inner-ring suburb of St. Louis located in western St. Louis County, Missouri. As of the 2020 census, the city's population was 29,461. Founded in 1853, the city is named after James P. Kirkwood, chief engineer of the Pacific Railroad. It was the first planned suburb located west of the Mississippi River.