De Leo Surname in Italy

The surname De Leo is mainly found throughout Southern Italy and the province of Rome. The rare variant De Leone likely originates from the Caserta area. Di Leo shares a similar distribution but is also notably present in Sicily, whereas Dileo is specific to the Bari area, especially Altamura and Barletta. Di Leone is uncommon, with roots in Campania—particularly in Mondragone, Cellole, and Calabritto—and also appears in the Cosentino area in Saracena and Morano Calabro. The very rare De Lio is typical of the Cosentino, including towns like Buonvicino, San Fili, and San Vincenzo la Costa, while Di Lio is mainly found in Bivona, Agrigento. Di Lione is characteristic of Colliano in Salerno province. These surnames most likely descend from an ancestor named Leo or Leonis, or originated through shortening of the names Pantaleo or Pantaleone.