Artavasdos, Latinized as Artabasdos or Artabasdus (Greek: Ἀρταύασδος or Ἀρτάβασδος, from Armenian: Արտավազդ, Artavazd, Ardavazt), was Byzantine Emperor of Armenian descent from June 741 or 742 until November 743. His reign constitutes an usurpation against Constantine V, who had retained control of several themes in Asia Minor.

The Armenian Artabasdus was appointed governor (stratēgos) of the Armeniac theme (Θέμα Άρμενιάκων, Thema Armeniakōn, was the successor of the Army of Armenia. It occupied the old areas of the Pontus, Armenia Minor and northern Cappadocia, with its capital at Amasea) by Emperor Anastasius II in c. 713. After Anastasius' fall, Artabasdus made an agreement with his colleague Leo, the governor of the Anatolic theme, to overthrow the new Emperor Theodosius III. This agreement was sealed with the engagement of Leo's daughter Anna to Artabasdos, and the marriage took place after Leo III ascended the throne in March 717.

Artabasdos was awarded the rank of kouropalates ("master of the palace") and became commander (count, komēs) of the Opsikion theme, while retaining control of his original command. In June 741 or 742, after the accession of Leo's son Constantine V on the throne, Artabasdus resolved to seize the throne and attacked his brother-in-law while the latter was traversing Asia Minor to fight the Arabs on the eastern frontier. While Constantine fled to Amorion, Artabasdus seized Constantinople amid popular support and was crowned emperor.