- Location: Castlebar, Mayo
- Country: Ireland
Westport (Irish: Cathair na Mart, meaning “city of the market”, historically anglicised as Cahernamart) is a town in County Mayo, Ireland.
It is situated on the west coast at the south-east corner of Clew Bay, an inlet of the Atlantic Ocean. Westport has a town centre designed by James Wyatt in 1780, in the Georgian architectural style. Its layout follows the medieval principles of urban design introduced by the Normans in the 13th century. The design for the town was commissioned by the Lord Sligo of the nearby stately home, Westport House, as a place for his workers and tenants to live. A particular feature is the incorporation of the river into the composition, contained for two blocks by low stone walls producing, on each side of the river, attractive tree lined promenades (The Mall) with several stone bridges over the river Carrow Beg.