Largest private foundations in Hawaii
| # | Foundation | City | Focus area | Total assets |
|---|---|---|---|---|
| 1 | Harold K L Castle Foundation | Kailua | Not listed | $171.3 million |
| 2 | Kosasa Foundation | Honolulu | Not listed | $159.4 million |
| 3 | Hau Oli Mau Loa Foundation | Honolulu | Not listed | $155.9 million |
| 4 | McInerny Foundation | Honolulu | Not listed | $139.0 million |
| 5 | Clarence T C Ching Foundation | Honolulu | Not listed | $131.8 million |
| 6 | Atherton Family Foundation | Honolulu | Not listed | $82.9 million |
| 7 | Tradewind Group Foundation | Honolulu | Philanthropy, Voluntarism & Grantmaking Foundations | $45.1 million |
| 8 | Samuel N & Mary Castle Foundation | Honolulu | Not listed | $38.6 million |
| 9 | Victoria S And Bradley L Geist Foundation | Honolulu | Philanthropy, Voluntarism & Grantmaking Foundations | $37.9 million |
| 10 | Maurice And Joanna Sullivan Family Foundation | Honolulu | Philanthropy, Voluntarism & Grantmaking Foundations | $34.1 million |
| 11 | Mamoru And Aiko Takitani Foundation Inc | Honolulu | Not listed | $31.3 million |
| 12 | James And Abigail Campbell Family Foundation | Kapolei | Not listed | $30.8 million |
| 13 | Strong Foundation | Honolulu | Not listed | $25.4 million |
| 14 | Charles & Mitch Ota Foundation | Honolulu | Philanthropy, Voluntarism & Grantmaking Foundations | $22.6 million |
| 15 | The Thomas J Vincent Foundation | Kaneohe | Philanthropy, Voluntarism & Grantmaking Foundations | $22.2 million |
| 16 | George N Wilcox General Trust | Honolulu | Not listed | $21.4 million |
| 17 | Garmar Foundation | Honolulu | Philanthropy, Voluntarism & Grantmaking Foundations | $19.4 million |
| 18 | Hmsa Foundation | Honolulu | Medical Research | $16.3 million |
| 19 | Cooke Foundation Limited | Honolulu | Not listed | $16.0 million |
| 20 | Germaine Hope Brennan Foundation | Honolulu | Philanthropy, Voluntarism & Grantmaking Foundations | $15.7 million |
| 21 | Hawaii Loa Ohana | Honolulu | Human Services | $15.1 million |
| 22 | Leonard Hoshijo Memorial Foundation | Honolulu | Housing & Shelter | $14.4 million |
| 23 | A L & Trini Kilgo Charitable Tr | Honolulu | Not listed | $14.3 million |
| 24 | Cades Foundation | Honolulu | Not listed | $14.1 million |
| 25 | Harry Chow & Nee Chang Chock Wong Foundation | Honolulu | Not listed | $13.7 million |
The full list includes all 611 Hawaii foundations with street address, ZIP, EIN, focus area, income and tax period, plus every other state.
Hawaii cities with the most private foundations
- Honolulu: 392
- Kailua: 21
- Kaneohe: 19
- Kailua Kona: 11
- Mililani: 11
- Hilo: 11
- Waipahu: 10
- Aiea: 9
- Kihei: 9
- Kahului: 8
Most common focus areas in Hawaii
- Philanthropy, Voluntarism & Grantmaking Foundations: 242
- Education: 62
- Arts, Culture & Humanities: 26
- Recreation & Sports: 14
- Human Services: 13
- Religion-Related: 13
- Environment: 12
- Animal-Related: 11
Where does this data come from?
The IRS Exempt Organizations Business Master File, downloaded in October 2026 and filtered to private foundations. Assets are as reported on each foundation's latest return on file. Foundations with no focus area code are shown as Not listed.