Casilda is a distinctive and uncommon given name of Spanish origin. It is derived from the Latin word 'casula', which means 'little hut' or 'small house'. In medieval Spain, it was often used as a surname due to its association with the Saint Casildis, who was believed to have lived in a small hut. Over time, the name evolved into a given name and gained some popularity during the Middle Ages. Today, however, Casilda remains relatively rare and unique, perhaps most famously borne by Casilda de la Cruz y de la Cerda, a Spanish noblewoman of the 13th century who was known for her beauty and kindness.
"Casilda's popularity peaked in the mid-20th century with a notable spike in births from 1954 to 1959, averaging six births per year during this period. However, its use has since declined significantly, with only five births recorded in 2023."