She is also known for playing Millie Bartham in Independent Television"South Homefront. She also played Nicolette in Independent Television"s Bernard"s Watch and Bernard. She provides the voice of Laura Large in the successful CBeebies show The Large Family.
She was also seen playing Tess Elliot in Independent Television"s medical drama: Harley Street playing the daughter of Suranne Jones.
She played Naomi in the stage play hit "Spur of the Moment" by award-winning playwright Anya Reiss at the Royal Court in London"s West End. In 2012, she made her feature film debut in the horror thriller "The Seasoning House" in the lead role of Angel, alongside Sean Pertwee, with CineVue stating: "Equally clear, is that 18-year-old Rosie Day has a long screen career ahead of her, as she effortlessly carries the entire film on her slight shoulders."
Rosie was chosen as one of Screen Internationals Stars of Tomorrow 2013.