Ruben I, (Armenian: Ռուբեն Ա;^[a] 1025/1035^{[citation needed]}–1095) was the first lord of Armenian Cilicia from c. 1081^{[citation needed]} until his death.

The Rubenids were descendants of the Bagratids.^[1]

He was 70^[2] (or 60) when he died;^{[citation needed]} he was buried at the monastery of Castalon.^[3]

The name of Roupen’s wife is unknown. His recorded children are:^{[citation needed]}

• Constantine I of Cilicia (1035/1055 – 24 February 1102 / 23 February 1103)^{[citation needed]}
• (?) Thoros of Marash (according to Rüdt-Collenberg, he was the brother of Constantine I)^{[citation needed]}

• Ghazarian, Jacob (2000). The Armenian Kingdom in Cilicia During the Crusades: The Integration of Cilician Armenians with the Latins, 1080-1393. Abingdon: RoutledgeCurzon. ISBN 9781136124181. OCLC 1079207547.

• The Barony of Cilician Armenia (Kurkjian's History of Armenia, Ch. 27)
• The Rupenids