- HAP International
- Harder+Company
- Hawaii Community Foundation
- Healthcare Georgia Foundation
- Hemenway & Barnes LLP
- HGF
- Icahn School of Medicine at Mount Sina
- Idealware
- Independent Sector
- Innovations for Poverty Action
- Institute of Development Studies (IDS)
- International Development Research Centre (IDRC)
- International Finance Corporation (IFC)
- Itad
- James Irvine Foundation
- Join Together
- Keystone Accountability
- Kresge Foundation
- Leap of Reason Ambassadors Community
- Les entreprises pour la Cité