Puerto Madryn (in Welsh, Porth Madryn) is a city in the province of Chubut in the Argentine Patagonia. It is the head town of the Viedma Department, and has about 58,000 inhabitants.
The town was founded on 28 July 1865, when 150 Welsh immigrants who came in the clipper Mimosa named the natural port Porth Madryn in honour of Sir Love Jones-Parry, whose estate in Wales was named "Madryn". The settlement grew as a result of the building of the Central of Chubut Railway by Welsh, Spanish and Italian immigrants. This line, opened in 1888, linked it to Trelew via the lower Chubut River valley. Puerto Madryn is protected by the Golfo Nuevo, which is formed by Península Valdés and Punta Ninfas. It is an important centre for tourists visiting the natural attractions of the Península Valdés and the coast.