Rheinfelden

Rheinfelden is:

 the name of two towns on the banks of the Rhine:
 Rheinfelden (Baden) in the Lörrach Rural District of Baden-Württemberg, Germany
 Rheinfelden, Switzerland in the Canton of Aargau, Switzerland, also
 Rheinfelden (district), a district in Aargau Canton.

 Other 
 Rudolf of Rheinfelden (or Rudolf of Swabia) (1025–1080), Henry IV, Holy Roman Emperor
 Rheinsfelden, eine suburg in the district of Glattfelden, in the Canton of Zürich, Switzerland