The province of Quebec and the Great Lakes Commission, the Great Lakes Fishery Commission and the International Joint Commission are represented at Great Lakes Executive Committee meetings.
Non-governmental organizations that have been recognized as Observers to the Great Lakes Executive Committee include:
- Alliance for the Great Lakes
- Benedictine Sisters of Erie, PA
- Blue Fish Canada
- Canadian Environmental Law Association
- Council of Great Lakes Governors
- Council of Great Lakes Industries
- Council of the Great Lakes Region
- Environmental Defence
- Freshwater Future
- Georgian Bay Association
- Georgian Bay Forever
- Great Lakes Ecoregion Network
- Great Lakes Policy Research Network
- Invasive Species Centre
- Lake Erie Waterkeeper
- National Wildlife Federation
- Northeast Midwest Institute
- Ohio Environmental Council
- Ontario Aquaculture Association
- Ontario Federation of Anglers and Hunters
- Pollution Probe
- SOS Great Lakes
- The Nature Conservancy
- Toxics Free Great Lakes Network
- Water Institute, University of Waterloo