Ouest (French, pronounced [wɛst] ⓘ) or Lwès (Haitian Creole; both meaning "West") is one of the ten departments of Haiti.

There are many native settlements in the department notably around Akaya, Azuei Lake, Yaguana, the island of Guanabo and Goava.

In 1793 the city fell to the British troops where they built the Fort-National until Toussaint gained it back for the French government.

Around 1772, Romaine-la-Prophétesse acquired a plantation named Trou Coffy in the department (likely in what is now Fondwa), becoming a prominent coffee grower and trader.

Caradeux the rough slave master in the region orderer their execution in Omòl.In 1791, Pétion, Pinchinnat, Beauvais, and more rebelled against the French authority and reclaimed their civil rights.

By September 23, Cangé left Léogane, marched toward Port-au-Prince, and attacked the Fort-Bizoton in Carrefour, Gabart was at the St-Joseph gate and Dessalines camped in Turgeau a neighborhood located east of the city.

Dessalines accepted with an exchange of prisoners and adjuvant-general Bonnet came back to the Haitians and gave the French 4 days to leave the city.

Thus on September 9 Port-au-Prince was freed from the French troops and Dessalines enter the city proudly with Pétion on his right and Gabart on his left.

On October 17, 1806, coming from Dessalinesville, Emperor Jacques 1st was ambushed and assassinated plunging the country into a civil war.

A part majority of the department lies in the Plaine-de-Cul-de-Sac which continues to the Dominican Rep. as the Hayo de Enriquillo.

The Bay of Port-au-Prince is the largest in the country and one of the biggest in the Caribbean harboring many islands, cays, and reefs.

The hills of Port-au-Prince consist of a mountain from the Massif de la Selle-Cordillera Meridional, where one can find multiple forests such as Foret-des-Pins and Parc-la-Visite.

The earthquake activities in the area are a result of the Enriquillo-Plantain-Garden fault going from Jamaica to the Dominican Rep passing through the Xaragua Peninsula and the Gonave Microplate.

For many years, agriculture was a part of the economy of the department, with the Arcahaie plain being a center for plantain, the Cul-de-Sac and Léogane being known for large sugar-cane plantations mostly for the production of rum, and the hills of Kenscoff cultivating different vegetables.

The bay harbors many ports of sizable capacity owned or operated by the state or private parties.