Welcome to Quality Buick GMC Cadillac. We are proud to be your Alton GMC, Alton Cadillac, and Alton Buick dealership, serving as a Belleville GMC, Belleville Cadillac, and Belleville Buick dealer. We are family owned and operated for over 50 years, serving all the surrounding cities – from St Louis to Edwardsville – making us a St. Louis GMC, St. Louis Cadillac and St. Louis Buick dealership conveniently located in Alton. Come by Quality Buick GMC Cadillac, conveniently located in Alton, if you are looking for a St. Louis GMC, St. Louis Cadillac, and St. Louis Buick dealer.