Ajaccio serves as the capital and largest city of Corsica, France, functioning as the prefecture of the Corse-du-Sud department and the head office of the Collectivité territoriale de Corse. Situated on the west coast of the island, it occupies a sheltered position at the foot of wooded hills on the northern shore of the Gulf of Ajaccio. The commune extends from the Gravona river to the pointe de la Parata, including the îles Sanguinaires, and represents the largest settlement on the island.

The original settlement declined during the Middle Ages before prospering after the Genoese constructed a citadel in 1492 south of the earlier town. Following the declaration of the Corsican Republic in 1755, Genoese forces held several citadels until French control was established. The city's development accelerated under Napoleon, who created major structural arteries, and it became one of the last European cities to join France before being liberated in 1943.

The urban area lies on a narrow coastal strip in the east, characterized by low-rise buildings and concrete towers, particularly on the heights and in the north. The landscape shows a dichotomy between the old city and modern structures, with the terrain becoming rugged in the west where the highest point reaches 790 meters. The harbour is protected by a peninsula, and the city encloses the entire Gulf of Ajaccio in its suburban form.

As the birthplace of Napoleon Bonaparte in 1769, the city features his ancestral home, the Maison Bonaparte, now a museum, alongside the Ajaccio Napoleon Bonaparte Airport. It is a tourist destination with a boardwalk along its coastline, excellent restaurants, and frequent cruise ship visits. The inhabitants, known as Ajacciens or Ajacciennes, reside in a town that blends historical heritage with modern Mediterranean tourism appeal.

Ajaccio has a population of 76,320 as of 2023 and experiences a Mediterranean climate with an average annual sunshine of 2,726 hours. The city holds the record for thunderstorms in metropolitan France during the reference period 1971–2000, averaging 39 days per year. Access is provided by Ajaccio Napoleon Bonaparte Airport, with direct flights from Paris and other European cities, as well as ferry routes from Marseille, Nice, and Toulon.