Luis Siret y Cels (26 August 1860, in Sint-Niklaas – 7 June 1934, in Las Herrerías) was a Belgian-Spanish archaeologist and illustrator.
He was born in Belgium, but when he was 21 he went to Cuevas del Almanzora (Almería) when he was contracted as a Mining Engineer in the Sierra Almagrera.
Los Millares is a Chalcolithic occupation site 17 km north of Almería, in the municipality of Santa Fe de Mondújar, Andalucía, Spain. The complex was in use from the fourth millennium BC (c. 3025 BC) to the end of the third millennium BC (c. 2000 BC) and probably supported around 1,000 people. It was discovered in 1891 during the construction of a railway. It was first excavated by Luis Siret in the succeeding years. Excavations are ongoing. Los Millares is the type site of the Chalcolithic Millaran culture.