Leo I (), also Levon I or Leon I, (unknown – Constantinople, February 14, 1140) was the fifth lord of Armenian Cilicia
Leo was captured after being invited to a meeting by the Byzantine Emperor John II Comnenus, who had sworn a false promise of peace.
Early life
Leo's father was Constantine I, lord of Armenian Cilicia.
After the death of Constantine I, Leo's brother Thoros I became the ruler.
Rule
thumb|300px|Armenian Cilicia and the [[Levant in 1135 CE.]]
Other authors (e.g., Jacob G. Ghazarian, Vahan M. Kurkjian) suggest that Thoros I was directly succeeded by Leo.
The (re-)occupation of Cilicia by the Byzantines
Eventually, John invited Leo to a meeting under a false promise of peace, where the prince was captured. Leo and two of his sons, Roupen and Thoros, were subsequently taken prisoner.