Xander Kostroma (born 7 April 1987, Swansea) is a Welsh jewellery designer best known for his ethical awareness in fashion. He received the Old Dy'vorian award in 2007/2008 and went on to create his brand Xander Kostroma in 2018. One year later, Xander was selected to present his idea of turning plastic waste into fashion jewellery in Istanbul, Turkey in collaboration with PlasticTwist, a project funded by The European Commission.