The name of Santanyí has very uncertain origins, but the most traditional and best accepted theory is the one that claims it is derived from the Latin Sanctus Agnus or Sancti Agnini, like a refference to the lamb, which appears on the town's coat of arms.
But Joan Coromines considers the origin to be Mozarab, while Guillem Rosselló Bordoy believes the name derives from the Arabic words Sanat Anawawil, which mean “coast of the huts of leaves”. Probably more close to the truth.
In the first half of the 19th century, the population grew considerably. Then in the middle of the century, it stagnated, though. There were serious demographic crisis and in the middle of the century the emigration began to Algeria, to inland Mallorca and even to Menorca.
From the second half of the 20th century everything changed with the tourism. The first visitors started appearing from 1950. Tourism changed the entire demographic structures of the municipality thanks to the people from the Iberian Peninsula, especially from the south, who arrived attracted by the jobs generated by this bussines.