Ksenia Sitnik was born on 15 May 1995 in the city of Mazyr, Belarus. Ksenia has an older sister named Nastya who herself has participated in children's song competitions. Ksenia currently lives with her family in the city of Minsk, Belarus.
She started her singing career at a very early age. She has participated in many vocal contests such as the festival Falling Stars in Nowa Ruda, Poland and The Golden Bee festival in Klimovichy, Belarus, both at the age of nine in the year 2004. Ksenia won first prize at the international children's contest at the Slavianski Bazaar in Vitebsk, Belarus in July 2005 and the same year also competed in The Star Light festival in Saint Petersburg, Russia.
Ksenia Sitnik won the Junior Eurovision Song Contest in 2005, where she represented her home country, Belarus, with the song My Vmeste. Despite the song not being particularly popular in pre-contest polls: for example, in the Europrediction poll, Ksenia came last with no points.Ksenia won, albeit narrowly - she had only three points more than the runner-up, Antonio José from Spain.
In November, 2006 Ksenia released a CD with accompanying music book called My Vmeste ("We Are Together"). She has released three music videos: Malenkiy Korablik ("Little Ship") in 2006, Prostaya Pesenka ("Simple Song") in 2007 and, most recently, Non-stop in 2009 .