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:
- Canadian Environmental Law Association
- Ontario Federation of Anglers and Hunters
- Georgian Bay Association
- Georgian Bay Forever
- Great Lakes Policy Research Network
- Invasive Species Centre
- Freshwater Future
- Alliance for the Great Lakes
- Council of Great Lakes Industries
- National Wildlife Federation
- Ohio Environmental Council
- Council of Great Lakes Governors
- Benedictine Sisters of Erie, PA
- Northeast Midwest Institute
- Council of the Great Lakes Region
- The Nature Conservancy
- Toxics Free Great Lakes Network
- Pollution Probe
- Environmental Defence
- Water Institute, University of Waterloo
- Blue Fish Canada