Uddevalla is a city and the seat of Uddevalla Municipality, Västra Götaland County, Sweden with 31,212 inhabitants in 2010.

It is located at the bay Byfjorden, of the south-eastern part of the sea known as Skagerrak. The beaches of Uddevalla are filled with seashells, and Uddevalla has one of the largest shellbanks in the world.

Uddevalla has a small port and once hosted a large shipyard called Uddevallavarvet, which in 1960 was the largest employer in Bohuslän. But in the 1970s all shipyards in Sweden experienced a recession which also led to the closure of Uddevallavarvet in 1985.

Uddevalla got its city rights in 1498 but was probably a place of trade long before that. Historically Uddevalla was part of Norway. Because of its location close to Sweden and Denmark, it was often besieged. In 1612 it was burnt by Swedish troops under the command of Jesper Mattson Krus and in 1644 it was again burnt, by the Swedish commander Harald Stake. In 1658, at the treaty of Roskilde, it was ceded to Sweden. A year later the Norwegians retook it, but in 1660 it was once again ceded to Sweden in the peace treaty of Copenhagen. Norway later repeatedly reconquered Uddevalla and the nearby fortress on Galleberg, the last time in 1788.