NIES is an initialism, which may refer to:
Newly industrializing economies: Four Asian Tigers Newly industrialized country
Various organizations: National Institute for Environmental Studies, Japan Northern Ireland Electricity Service Nanjing Institute of Environmental Sciences, China National Industry Extension Service, Australia
Various tools or systems: National Imagery Exploitation System, of the National Geospatial-Intelligence Agency, United States Department of Defense
Various academic studies: Nauru Island Effect Study, carried out by the[United States Department of Energy from September 2002 to June 2003 to study the island's influence on atmospheric radiation measurement (ARM) at a measurement site located on Nauru. See also Nies (surname)