Hornsby is a suburb of Sydney in New South Wales, Australia. Hornsby is located 25 kilometers northwest of the city center and is the administrative headquarters of the administrative district (LGA) Hornsby Shire. The name Hornsby derives from Constable Samuel Henry Horne. He was involved in the arrest of the two escaped convicts Dalton and MacNamara on June 22, 1830 and received a piece of land, which he called Hornsby Place.