The spokesperson tells Us that Clooney appears in a sketch scene for ITV's Christmas charity fundraiser, Text Santa, which is set in Highclere Castle, the setting for Downton Abbey.
Sadly, Amal Alamuddin's fiance's gig is merely a stand-alone film and Clooney won't be appearing in the upcoming fifth season. The handsome hunk is, however, a fan of the BBC show!
In May, Clooney took his soon-to-be wife on a tour of Highclere Castle, which is located in Hampshire, a county outside London. At the time, a source told Us, "Highclere is sometimes open to the public but this day it wasn't, so they were the only ones there. They spent a few hours there before they returned to their hotel."
ITV's Text Santa raises money and awareness for six UK based charities offering life-changing services to people in communities.