Hassi Messaoud is a town located in the Ouargla Province of eastern Algeria, situated approximately 85 kilometres southeast of the city of Ouargla. As of 2008, the town had a population of 45,147 people, reflecting an annual growth rate of 1.1%, which was the lowest recorded in the province.
The town is primarily known as Algeria's first energy town and serves as a major oil refinery hub. It was named after the country's first oil well, where oil was discovered in 1956. This discovery led to rapid growth for the settlement, which now hosts offices and bases for all of the major oil and gas companies. Within a 25-kilometre radius of the town, there are currently over 800 wells. Additionally, an early water well dug in 1917 is located on the airport side of the town.