Vallenar is a city and commune in Atacama Region, Chile. It is the capital of the Huasco Province and is located in the valley of the Huasco River. Vallenar has 52,000 inhabitants. Its main activities are farming and mining. It was founded as San Ambrosio de Ballenary by Ambrose O'Higgins in 1789, after his birthplace in Ballynary in County Sligo, Ireland.
Llanos de Challe National Park is located northwest of the city of Vallenar.