Stephan Nieuwesteeg started playing the violin at the age of 5 at the music school in Waddinxveen with Bastienne Prins. In 2001 he was admitted to the young talent department of the Royal Conservatory in The Hague where he studied with Koosje van Haeringen. He continued his violin studies in vocational training with Theodora Geraets, with whom he successfully completed his studies in June 2014.
Stephan took master classes with Peter Brunt, Mieke Biesta, Philippe Graffin, Jaring Walta and Petru Munteanu, among others. He participated in various competitions including the Oskar Back Competition (semi-final), Davina van Wely Competition and the Iordens Viooldagen (third prize), Princess Christina Competition (chamber music ensemble with Pieter van Loenen and Sonia Min).
Stephan played in the National Youth Orchestra.
Since 2013 he is part of the Ciconia Consort.
Stephan plays an instrument built by Marten Cornelissen, made available to him by the National Musical Instruments Fund.