Family name Castellanus (Castillan 
, Castellan 
, Castelan ) , across the world, is a common cognomen. The last name Castellanus is characteristic of Mexico, where it is quite a common surname, Italy, where it is quite a rare surname, and Guatemala. Not in comparison with a country's population, it is commonest in Mexico, Italy, and Brazil. Much less frequently, Castellanus is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Castillan | Philippines, France, Canada, United States, Democratic Republic of the Congo |
| Castellan, Castelan | Brazil, France, Mexico, United States, Italy |
| Castellanus | United States |
Castigliano, and Chatelaine
| vincentius castellanus artist |
|