| I.O.I. institutional members | |
| Australia | Commonwealth Ombudsman & Defence Forces Ombudsman, Canberra City, Australia |
| Ombudsman, Northern Territory, Australia | |
| The NSW Ombudsman, New South Wales | |
| Queensland Ombudsman, Australia | |
| The Ombudsman SA, South Australia | |
| The Ombudsman Tasmania, Australia | |
| The Ombudsman Victoria, Australia | |
| The Ombudsman Western Australia | |
| China | Office of the Ombudsman, Hong Kong |
| The Control Yuan of the Republic of China, Taiwan | |
| Cook Islands | Office of the National Ombudsman, Cook Islands |
| New Zealand | National Ombudsman, Te Kaitiaki Mana Tangata, New Zealand |
| Papua New Guinea | Ombudsman Commission of Papua New Guinea |
| Philippines | Ombudsman |
| I.O.I. individual members | |
| Australia | University of Technology, Faculty of Law, Sydney, Australia |
| Regional Ombudsman Association | |
| Australian & New Zealand Ombudsman Association |
- Albania
- Antigua
- Argentina
- Armenia
- Australia
- Austria
- Azerbaijan
- Belgium
- Bermuda
- Botswana
- British Virgin Islands
- Bulgaria
- Burkina Faso
- Canada
- Cayman Islands
- China - Hong Kong
- China - Macao
- Cook Islands
- Croatia
- Cyprus
- Czech Republic
- Denmark
- Denmark - Greenland
- Djibouti
- Estonia
- Europe
- Fiji Islands
- Finland
- France
- Gambia
- Germany
- Gibraltar
- Greece
- Guatemala
- Hungary
- Iceland
- India
- Indonesia
- Iran
- Ireland
- Israel
- Italy
- Ivory Coast
- Japan
- Jordan
- Korea, Republic
- Latvia
- Lesotho
- Lithuania
- Luxembourg
- Macedonia
- Malawi
- Mali
- Malta
- Mauritius
- Mexico
- Moldova
- Namibia
- Netherlands
- New Zealand
- Norway
- Pakistan
- Papua New Guinea
- Peru
- Poland
- Portugal
- Principat d'Andorra
- Puerto Rico
- Romania
- Samoa
- Santa Lucia
- Serbia
- Sint Maarten
- Slovak Republic
- Slovenia
- South Africa
- Spain
- Sri Lanka
- Sudan
- Sweden
- Switzerland
- Taiwan
- Tanzania
- Thailand
- Tonga
- Trinidad & Tobago
- Tunisia
- Uganda
- Ukraine
- United Kingdom
- USA
- Uzbekistan
- Vanuatu
- Zambia
ADHÉRENT