莱茵费尔登（Rheinfelden）是瑞士阿尔高州的一个市镇，位于巴塞尔以东15公里处。名字的意思是莱茵河的流域，其位置处于莱茵河上游。该城市和德国巴登-符腾堡的莱茵费尔登隔莱茵河相望。两座城市原来为一座城市，直至1802年拿破仑一世确定了瑞士和德国的边界，但是在经济和社会方面仍紧密相连。

莱茵费尔登面积为16.03平方公里。其中3.32平方公里（20.7％）为农业用地，8.01平方公里（50.0％）为森林。其余土地3.62平方公里（22.6％）为建筑物或道路，1.07平方公里（6.7％）为河流或湖泊，0.01平方公里（0.1％）为不毛之地。

Rheinfelden (Swiss German:Rhyfälde, [ˈɾiːfæld̥ə]) is a municipality in the canton of Aargau in Switzerland, seat of the district of Rheinfelden. It is located 15 kilometres east of Basel. The name means the fields of the Rhine, as the town is located on the Hochrhein. It is home to Feldschlösschen, the most popular beer in Switzerland. The city is across the river from Rheinfelden in Baden-Württemberg; the two cities were joined until Napoleon Bonaparte fixed the German–Swiss border on the Rhine in 1802 and are still socially and economically tied.