Saint Louis Art Fair in Downtown Clayton. The Saint Louis Art Fair is recognized as one of the top annual art fairs in the country. It is held over three days, Friday-Sunday, September 5th-7th, and located on the streets of the Clayton Business District (see website for map). Fair goers will enjoy live music, a multitude of artists displaying their works in a vast array of mediums, food from top St. Louis restaurants, and children activities. This event is FREE to attend. See website for more information.