Gijs Leenaars grew up in Nijmegen, where he studied piano alongside his secondary school education. A year after completing his VWO he obtained the teaching certificate B for piano. He then received orchestra conducting lessons from Joop van Zon, studied choral conducting with Jos Vermunt and singing with Paula de Wit.
Gijs Leenaars is artistic director of Bachkoor Holland and Capella Frisiae, and was assistant conductor with the Radio Chamber Philharmonic and the Radio Philharmonic Orchestra. He is a regular guest conductor with La Filarmonica di Torino in Italy and a repetiteur with Cappella Amsterdam and the Nederlands Kamerkoor. In recent seasons he has conducted concerts with Cappella Amsterdam, the Residentie Orkest, the Rotterdam Philharmonic Orchestra and the Radio Chamber Philharmonic, among others.
Gijs Leenaars has worked regularly with the Groot Omroepkoor since the 2004-2005 season, first as assistant conductor and then as guest conductor. In the 2012-2013 season he succeeded Celso Antunes as chief conductor of the Groot Omroepkoor. As of the 2015-2016 season, he will resign from this position, having accepted the position of principal conductor at the Rundfunkchor Berlin.