Green Island Brook is a local service district and designated place in the Canadian province of Newfoundland and Labrador.
Green Island Brook is in Newfoundland within Subdivision C of Division No. 9.
As a designated place in the 2016 Census of Population conducted by Statistics Canada, Green Island Brook recorded a population of 143 living in 69 of its 83 total private dwellings, a change of from its 2011 population of 161. With a land area of , it had a population density of in 2016.
Green Island Brook is a local service district (LSD) that is governed by a committee responsible for the provision of certain services to the community. The chair of the LSD committee is Donald Macey.