Affton is an unincorporated inner-ring suburb of St. Louis, located in St. Louis County, Missouri. Its population at the 2010 census was 20,307.
Even till the 1930s, Affton was a small town with a population under 1000. It was disincorporated in 1935 and has remained the same till now. In the last few decades, the library has been remodeled. A number of new buildings have been constructed. Addtions have also been made to the local school.
The population predominantly comprises White Americans.