Globally, Castiau (Castiau 
) is an extremely rare girly first name. Much more frequently, Castiau is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Castiau | Cyprus, United Kingdom, Belgium, South Africa, France |
| adelson castiau Belgian politician, BE (b. 1804) |
|
Mr, Yseult, Xavier, Mathieu, Melissa, Michael, Anthony, Pauline, Laurent, Lindsay, Thierry, Estelle, Vincent, Olivier, Caroline, Claudine, Clemence, Jonathan, Jean Luc, Jean-Luc, Thibault, Frederic, Thomas, Julien, Joelle, Pierre, Ms, Vã, Loã, Jain, Jean, Evan, Casti, Katty, Doran, Louis, Isabelle, Loïc, Naomy, Margot, Michel, Sophie, Anaïs, Aricia, Arthur, Amanda, Axelle, Pascal, Jessi, and Séverine