In 1899, D. & T. Hamilton of Edinburgh installed a three-manual organ against the east wall of New Greyfriars. This had originally been made in 1866 by the same firm for Park Parish Church, Glasgow. It was overhauled in 1901 by Charles and Frederick Hamilton of Edinburgh. When the dividing wall between Old and New Greyfriars was removed in 1938, this organ was rebuilt in the north-west gallery by Gray & Davison of London. The console was placed at ground level under the opposite arcade until it was moved to the east end during the 1950s. It was overhauled again in 1960 by H. Hilsdon of Glasgow and scrapped in 1990 after its replacement by the current organ.