The name Atreus means Fearless, Brave and is of Greek origin. Atreus is a name that's been used primarily by parents who are considering baby names for boys.
In Greek mythology, Atreus was a king of Mycenae in the Peloponnese, father of Agamemnon and Menelaus.
Atreus is also the name of an asteroid and a video game character in God of War.