Castries is the capital of Saint Lucia.

It is also the largest city in Saint Lucia, an island country in the Caribbean. The urban area had a population of approximately 20,000, while the eponymous district had a population of 70,000 on 22 May 2013. Castries is in a flood plain and is built on reclaimed land. It houses the seat of government and the head offices of many foreign and local businesses. The city is laid out in a grid pattern. Its sheltered harbor receives cargo vessels, ferry boats, and cruise ships. It houses duty-free shopping facilities such as Point Seraphine and La Place Carenage. The city is well served by a bus system and taxi service. St Lucia's main post office is in Castries.