Sian Evans is a Welsh singer. She is front woman and singer-songwriter of the band Kosheen, a trip-hop/drum & bass group that had their first two albums rise into the Top Ten of the UK Albums Chart between 2001 and 2003. She has also joined a list of Welsh artists to have topped the UK Singles Chart with collaboration on the track "Louder" with DJ Fresh. Kosheen went on hiatus in 2016 and started touring again in 2019.

Kosheen is a British electronic music group based in Bristol, United Kingdom. The group consist of singer-songwriter Sian Evans, songwriter-producer Ron Mcelroy and drummer Mitchell Glover. The name Kosheen derives from the name of a North American Apache warrior, Cochise. When in Japan, it was discovered that a combination of the Japanese words for "old" and "new" would make "Kosheen" in Japanese.