A jury at Cardiff Crown Court yesterday convicted him of raping an intoxicated 15-year-old at a house party in Newport, South Wales in 2011.
Morris, 42, had claimed that a sleep disorder meant he had no recollection of the attack on the minor.
Judge Daniel Williams told him: "You are facing a substantial custodial sentence."
Prosecutor Sue Ferrier said: "Morris took an interest in the girl - winking at her, helping her pour drinks and even offering her to stay with him in London. The girl got drunk on cocktails and her father put her to sleep in an upstairs room."
The now part-time actor, who lives in London, was in one episode of Hollyoaks in 2001 and also featured as an extra in Michael Caine's Shiner.
Morris will be sentenced in the New Year.