Magden (Swiss German: Magde) is a municipality in the district of Rheinfelden in the canton of Aargau in Switzerland.It is located 3 km to the south of the Rheinfelden. Its Roman name was Magdinium, and it is the site of the ancient Magdalener spring which today serves as the water supply of the Feldschlösschen brewery in Rheinfelden, which was recently acquired by Carlsberg.