Canton of Basel-Stadt or Basel-City (German: Kanton Basel-Stadt [ˌbaːzl̩ˈʃtat] ; Romansh: Chantun Basilea-Citad; French: Canton de Bâle-Ville [bɑl.vil]; Italian: Canton Basilea Città) is one of the 26 cantons forming the Swiss Confederation. It is composed of three municipalities with Basel as the capital. It is traditionally considered a "half-canton", the other half being Basel-Landschaft , its rural counterpart.

Basel-Stadt is one of the northernmost and lowest cantons of Switzerland, and the smallest by area. The canton lies on both sides of the Rhine and is very densely populated. The largest municipality is Basel, followed by Riehen and Bettingen .