Although the newly-released image teases the award-winning actress' official return to the Netflix series, Foy has already made a cameo in season three - as seen in the trailer for those who have yet to devour the latest installment.
In fact, the 35-year-old appeared in the very first scene as the season kickstarted with the Queen (Colman) examining two versions of her official portrait: the old one bearing Foy's profile against the new, with Colman's face.
Despite members of the royal staff trying to convince Her Majesty that the new portrait is an "elegant reflection" of her transition through the years, the Queen is less than impressed.
"A great many changes," Colman declares. "Nothing one can do about it. One just has to get on with it."
News of Foy's return comes amid speculation that Imelda Staunton, who famously took on the role of Dolores Umbridge in the Harry Potter franchise, will be crowned the Queen in season five.
Netflix has yet to confirm the reports, noting: "We are currently filming season four of The Crown but have not commissioned any further seasons as yet, therefore any news on casting remains pure speculation."
But after binge-watching season three in one fell - rather well spent - weekend, who can blame us for thinking ahead?