Sarah Nicole Harding (17 November 1981 – 5 September 2021) was an English singer, model and actress. Her professional career began in 2002 when she successfully auditioned for the ITV reality series Popstars: The Rivals, during which Harding won a place in the girl group Girls Aloud. The group achieved twenty consecutive top ten singles (including four number ones) in the UK, six studio albums that were certified platinum by the British Phonographic Industry (BPI), two of which went to number one in the UK, and accumulated a total of five BRIT Award nominations. In 2009, Girls Aloud won "Best Single" with their song "The Promise".

During the group's break, Harding began acting, appearing in Bad Day, the BBC television film Freefall, Run for Your Wife, and St. Trinian's 2: The Legend of Fritton's Gold. Harding contributed three solo songs to the soundtrack of St. Trinian's 2. She also modelled for Ultimo lingerie. In late 2012, she reunited with Girls Aloud to celebrate their tenth anniversary. In early 2013, they announced that they had split up. In 2015, the singer briefly appeared in Coronation Street, and released her first extended play record, Threads. She won Celebrity Big Brother 20 in 2017.