Cognomen San Tiago (San Tiago 
) , worldwide, is a very rare last name. The surname San Tiago is habitual in Philippines, where it is a very rare surname, and Mexico, where it is an extremely rare surname. Much less frequently, San Tiago is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| San Tiago | Mexico, Brazil, Philippines |