Alexius
| Gender | Male | 
|---|---|
| Language(s) | Greek | 
| Other names | |
| See also | Alexia (female) Alexey | 
Alexius is the Latinized form of the given name Alexios (Greek: Αλέξιος, polytonic Ἀλέξιος, "defender", cf. Alexander), especially common in the Byzantine Empire. The female form is Alexia (Greek: Αλεξία) and its variants such as Alessia (the masculine form of which is Alessio) in Italian.
The name belongs to the most ancient attested Greek names (a-re-ke-se-u in the Linear B tablets KN Df 1229 and MY Fu 718).