Former Coronation Street actress Michelle, who is married to former TOWIE star Mark Wright, is set to play Ursula, a vestal virgin on the show.
A source told The Sun: "Everyone on set absolutely loved her. She was brilliant."
The newspaper reports that Michelle travelled to the show's set in Bulgaria to film her episode, which will air next year.
Plebs follows the story of three desperate young men who reside in ancient Rome. Having appeared on our screens since March 2013, it will return next year with its third series.
Since quitting Corrie as barmaid Tina McIntyre last year, Michelle went on to star in BBC One drama Ordinary Lies as car sales receptionist Tracy. She also bagged a "gritty" role in Chris Green's new loan shark film, Strangeways Here We Come, where she played an "anxious, fragile and introverted" young girl called Demi.
She's also landed a lead role in BBC One army drama Our Girl as medic Corporal Georgie Lane.
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