Adra was founded by the Phoenicians during the eighth century BC, however, according to archaeological remains found on the Montecristo hill, a site classified as being of important cultural significance, the area has a Punic past. Punic control of the colony is thought to have been established from the fourth century BC, and at the end of the second century BC it passed to the control of the Roman Empire in the province of Hispania Ulterior. Evidence suggests that the Roman presence in Adra persisted for three centuries.
During the Roman era, the settlement of Abdera was a port of departure for minerals sourced from the nearby mountains of Gádor, as well as for wood and salted fish, garum and liquefied pasta made from the remains of meat and the viscera of fish and shellfish, all of which were key Roman delicacies.
After a population decline between the years 23 BC and 25 AD, Adra experienced a a moment of great splendor around 175 and 225 AD. From the third century, and coinciding with the crisis of the Roman Empire, the city entered a period of gradual decline that lasted until the sixth century AD. The Byzantine and Visigoths settled here around the sixth and seventh centuries AD.
The Islamization of the municipality did not take place until the ninth century AD, when its urban population was remodeled, specifically around the current neighborhood of La Alquería. Legend says that the last Nasrid leader of Granada, Boabdil el Chico, left the Iberian Peninsula from the port of Adra in 1492 on his way to North Africa, after leaving Granada fleeing the Catholic Monarchs. The story goes that, once at sea, the prince turned his gaze in the direction of Adra and threw his sword into the sea, promising that one day he would return for her. Years later, he would choose the city of Adra again as a gateway during an attempt to reconquer the peninsula.
Adra was also the base port for the Castilian troops that ended the Moorish rebellion in Las Alpujarras, in which the captains who won the Battle of Lepanto participated.
The town began to reestablish itself in the nineteenth century under industrialization and the creation of sugar factories and lead smelting, although its fishing has always been important, especially sardines, anchovies, sea breams and seabass (which are today bred on marine farms), tuna and ‘Canutera’ melva, achieving great prestige with its canning industry since the thirties.
Today, Adra survives on intensive ‘greenhouse’ agriculture, producing selected vegetables and fruits that are distributed in the best European markets. It also benefits greatly from tourism, thanks to its location by the sea, having several beaches with blue flag quality approval. In 2005, it hosted the cultural branch of the Mediterranean Games.