Basel-Stadt is a canton in northern Switzerland, situated on both sides of the Rhine where it forms a knee near the border with France and Germany. It is one of the country's smallest cantons by area, covering 37 square kilometers, and is traditionally considered a half-canton alongside Basel-Landschaft. The capital city of Basel serves as the administrative center for this densely populated region, which lies at the tripoint where Switzerland, France, and Germany meet in the middle of the Rhine.

The canton was created in 1833 following political quarrels and armed conflict that led to the partition of the historic Canton of Basel, which had joined the Old Swiss Confederacy in 1501. The separation occurred on August 26, 1833, dividing the agricultural areas from the city. Although movements for reunification gained momentum after 1900, proposals in 1969 and 2014 were rejected by voters in Basel-Landschaft, cementing the division into two distinct political entities.

The canton comprises three municipalities: Basel, Riehen, and Bettingen. Basel is divided by the Rhine into Grossbasel on the south and west banks, containing the medieval old town, and Kleinbasel on the north bank. The region features a mix of Romanesque architecture, such as the Münster cathedral, and contemporary works by renowned architects. The area is also home to the Dreiländereck monument, marking the convergence of three nations.

Basel is renowned for its vibrant cultural scene, including the Basler Fasnacht carnival, which begins at 4am with Morgestraich and lasts for 72 hours. The city hosts major international events like Art Basel and BaselWorld, alongside the Autumn Fair, the largest in Switzerland. Local culinary specialties include Basler Läckerli and Brunsli biscuits. The canton is also famous for its banking sector and as the worldwide seat of the Bank for International Settlements.

The population of the canton was 200,031 as of 2024. It serves as Switzerland's seventh-largest economic center with the highest GDP per capita, driven by chemical and pharmaceutical exports. Transport links include the Basel-Mulhouse airport located in France, a major railway station connecting to Paris and Berlin, and a significant port on the Rhine offering direct sea access for landlocked Switzerland.