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 432 square kilometres and at the 2021 census, the Shire had a population of 62,895. It was formed in 1994 from the merger of parts of the Shires of Eltham, Diamond Valley, Healesvā¦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 432 square kilometres and at the 2021 census, the Shire had a population of 62,895. It was formed in 1994 from the merger of parts of the Shires of Eltham, Diamond Valley, Healesville and the City of Whittlesea. The Shire uses the tag-line The Green Wedge Shire. The Nillumbik Council offices are located in Civic Drive, Greensborough.