The origin of surname Mancilla is the region of Tuscany in Italy.
Although people were originally known only by their first names, it became necessary to adopt a second name to identify due to population growth.

The most common type of family name found in the region was the surname that derives from the name of the father.
During the Middle Ages the Italians adopted the patronymic system for surnames.
Then in Italy during the Christian age, people often gave as a second name to their children the names of saints or biblical figures.
The nicknames as surnames usually reflected the physical characteristics of the first member of the lineage.
Italian surnames have a large number of forms in comparison with other European surnames because they reflect regional variations and the many dialects of Italian.

The local names describe a region or place where they lived the first members of the lineage.
The occupational surname, which are less common than other types of names, dating from the feudal age.
The occupational surname were not hereditary at first until the same occupations were hereditary.
Mancilla's surname as a nickname and start describing a person who was equally adept with both hands.
The name Mancilla derives from the word Mancino which means ambidextrous.