This was the area of the ancient Samnite city of Aquilonia and in the plains were found ruins of ancient buildings dating back to Roman times.
The name of San Vittore del Lazio comes from the Benedictine church of Monte Cassino around which the town formed around the tenth century. At that time people were seeking shelter in churches or castles from the Saracens.
The first mention of the castle is in a document of 1057, in the archives of the Abbey of Montecassino. Despite some disagreement in the fourteenth century on the feudal relations, San Vittore and its castle were always faithful.
San Vittore has been involved in several incidents of war in the Middle Ages and up to the early sixteenth century, when during the reign of Kingdom of Naples peace came with the Spanish.
At the end of the eighteenth century it was heavily damaged by the invasion of the French troops. San Vittore del Lazio was then heavily bombed during the Second World War when the war front had settled right in front of the village.