Andernos-les-Bains is a commune in the Gironde department in southwestern France.

Andernos-les-Bains is a located on the northeast shore of Arcachon Bay. To its northwest is the town of Arès.

Andernos-les-Bains consists of four other small communities: Taussat, Cassy, Lanton and Audenge. All these villages are characterized by their oyster farms and small fisheries. For many years, the oyster and fishing industry provided the main income to the area. More recently, tourism has become a strong economic factor in the area.

The bay was well known for the Portuguese oyster which died out during 1970-1972 because of gill disease. But a new oyster was found, the "Pacific oyster". Nevertheless, in 1974 the new oyster developed a disease caused by the paint used on fishing boats. An oil tanker spill in 1978 further damaged the oyster industry, which continued to suffer until 1981. The oyster industry suffered substantially around the bay. This was a disaster for whole of France and Europe as the Archachon oyster is a world famous delicacy.

Since 2000 the oyster industry has been recovering and now nearly 15,000 metric tons are produced per year.

Andernos-les-Bains has a 5.4 km (3.4 mi) long sand beach.