The 31-year-old former Girls Aloud member shared the news on Twitter by posting a photograph of her private dressing room, alongside the caption, "My quarters! Swing by for a tea."
She then followed it up with the tweet, "I'm doing a little part in a film. Thank you everyone today (sic),"
Coyle's new mystery role comes seven years after she first mentioned her desire to carve out an acting career.