It has borders to Inzlingen and Rheinfelden (Baden) in Germany, and Riehen (BS), Birsfelden (BL) and Kaiseraugst (AG) in Switzerland.

Grenzach-Wyhlen was established on January 1, 1975 from the two independent municipalities Grenzach and Wyhlen in the course of the Baden-Württemberg reform of the local governments.

First settlements in today's municipality area are of Celtic origin, belonging to the Hallstatt culture in the early 1st millennium BC.

The first documented mentioning of the settlement was in the 13th century CE, when Grenzach and Wyhlen were under Frankish rule.

With the founding of the Grand Duchy of Baden Wyhlen also became Badisch, so that after more than 500 years the two places were again under the same territorial rule.