Basil Mesardonites (Greek: Βασίλειος Μεσαρντονίτης, died 1016) was the Catapan of Italy, representing the Byzantine Emperor there, from 1010 to 1016 or 1017.
He succeeded the catapan John Kourkouas, who died fighting the Lombards, then in rebellion under Melus, early in 1010.
In March, Basil disembarked with reinforcements from Constantinople and Leo Tornikios Kontoleon, the strategos of Cephalonia.
The Greek citizens of the city negotiated with Basil and forced the Lombard leaders, Melus and Dattus, to flee.
Modern scholars such as Guilou and Vannier identify Basil Mesardonites with Basil, a member of the Argyros family and a brother of the future emperor Romanos III, who is reported by the chronicler John Skylitzes to have also been active against Melus's rebels.