Lörrach (German pronunciation: [ˈlœʁax] ) is a city in southwest Germany, in the valley of the Wiese, close to the French and the Swiss borders. It is the district seat of the district of Lörrach in Baden-Württemberg. It is the home of a number of large employers, including the Milka chocolate factory owned by Mondelez International. The city population has grown over the last century; with only 10,794 in 1905, it has now increased its population to over 50,000.

Nearby is the castle of Rötteln on the Wiesental, whose lords became the counts of Hachberg and a residence of the Margraves of Baden; this was destroyed by the troops of Louis XIV in 1678, but was rebuilt in 1867. Lörrach received market rights in 1403, but it did not obtain the privileges of a city until 1682.