Rosa Isabel Mutya Buena (born 21 May 1985) is a British singer and songwriter who rose to fame as a member of girl group the Sugababes. With the Sugababes, Buena had four UK number one singles, an additional six top-ten hits and three multi-platinum albums. After leaving the group in December 2005, she released her debut solo album, Real Girl in June 2007. In October 2010, Buena released a compilation album dedicated to British singers, titled Sound of Camden: Mutya Buena.
On 20 July 2012, Buena and her former Sugababes bandmates Donaghy and Buchanan confirmed their reunion. The original trio originally opted to release music under the name MKS (Mutya Keisha Siobhan), releasing one single Flatline in 2013. In September 2019, the group officially confirmed their return as the Sugababes.
Buena was born in Kingsbury, London and attended Kingsbury High School. Her father is Filipino and her mother is of Irish descent. On 23 March 2005, Buena gave birth to her daughter Tahlia. Buena dedicated a song to her late sister Maya on the Sugababes album, Three.