Last name Thaddius (Thaddius 
) , worldwide, is a rare family name. The cognomen Thaddius is habitual in Cameroon, where it is a rare surname, Nigeria, and Malaysia. Likewise, Thaddius is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thaddius | Malaysia, Philippines, Nigeria, United States, Cameroon |