Reinbert de Leeuw (8 September 1938 – 14 February 2020) was a Dutch conductor, pianist and composer. He was born in Amsterdam.
In 1974, he founded the Schönberg Ensemble. They mainly focused on performing works by the Second Viennese School. He composed the piece Etude (1983–1985) for the strings of the ensemble.
De Leeuw regularly conducted the Netherlands' major orchestras and ensembles, including the Royal Concertgebouw Orchestra, New Sinfonietta Amsterdam, Residentie Orchestra The Hague and ensembles such as the Netherlands Chamber Choir, the ASKO, the Netherlands Wind Ensemble, and the orchestras of the Dutch Public Radio.
In the 1995–96 season, he was the centre point of the 'Carte Blanche' series in the Concertgebouw Amsterdam.
He was involved in the organization of the series 'Contemporaries' at the Concertgebouw Amsterdam.