The Shire of Nillumbik is a local government area in Victoria, Australia. It contains outer northern suburbs of Melbourne and rural localities beyond the urban area. It has an area of 435 square kilometres and at the 2011 Census, the Shire had a population of 60,342. It was formed in 1994 from the merger of parts of the Shires of Eltham, Diamond Valley, Healesville and the City of Whittlesea.