Globally, Quilliam (Quilliam 
) is a very rare primarily masculine, but scarcely female first name. The first name Quilliam is habitual in Northern America, particularly the United States, where it is an extremely rare predominantly masculine, but scarcely female name. Much more prevalently, Quilliam is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Quilliam | United Kingdom, Canada, Australia, United States, Isle of Man |