Data / Foundation grants / Harold KL Castle Foundation
Harold KL Castle Foundation: 104 grants to organizations, $6.7 million (tax year ended December 2024)
Harold KL Castle Foundation, a private foundation in Kailua, HI, paid 104 grants to organizations totaling $6,703,501 in its tax year ended December 2024, according to its Form 990-PF filed with the IRS on November 13, 2025. The largest was $550,000 to Social Finance Inc in Boston, CA for proposal to serve as hawaii renewable learning fund manager [6086; pc].
SpecStream is the live web data engine for teams and agents. It reads every private foundation's Form 990-PF as the IRS publishes it, and this page is that reading. Ask for the foundations that fund your cause in your state, with the amounts and purposes, and new grants arrive in your sheet, CRM, Slack or agent as the returns are filed.
- EIN
- 996005445
- Based in
- Kailua, HI
- Assets
- $199,458,982
- Grants paid
- $6,685,968
- Tax year ended
- December 2024
Grants paid, tax year ended December 2024
From the Form 990-PF filed November 13, 2025, IRS object ID 202543179349104159. It reported $6,685,968 in grants paid; 104 grants to organizations are listed.
| Recipient | Location | Purpose | Cause | Amount | Source |
|---|---|---|---|---|---|
| Social Finance Inc | Boston, CA | Proposal to serve as hawaii renewable learning fund manager [6086; pc] | $550,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | Soar higher - support for windward oahu schools to participate as a gear up 6-16 model [5173; pc] | $529,240 | apps.irs.gov | |
| Hawaii Community Foundation (HCF) | Honolulu, HI | Support for a second round of contributions to the holomua pooled fund whose goal is to improve marine resources management in hawaii through a suite of efforts built on four pillars: place-based plan | $500,000 | apps.irs.gov | |
| Kuaaina Ulu Auamo (kua) | Kaneohe, HI | To support and strengthen this critically important backbone organization and its three community-driven networks for ocean management in hawaii. [5598; pc] | $500,000 | apps.irs.gov | |
| Hawaii Community Foundation (HCF) | Honolulu, HI | Pilina fund 2.0 [5618; pc] | $400,000 | apps.irs.gov | |
| The Nature Conservancy of Hawaii | Honolulu, HI | Advancing community-based marine management to reach 30x30 goals [5660; pc] | $280,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | To extend windward community college's groundbreaking hoolei scholarship that ensures all public school graduates in the koolau region can afford to attend community college [6140; pc] | $214,286 | apps.irs.gov | |
| Hawaii Hospital Education and Research Foundation (hherf) | Honolulu, HI | To retrofit doe classrooms for healthcare pathways in partnership with hawaii 3r's, g70 and hawaii pacific health [6363; pc] | $150,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | Hawaii p-20 core support 2022-2025 [5465; pc] | $150,000 | apps.irs.gov | |
| Windward School District | Kaneohe, HI | To internally drive windward doe schools towards aina aloha mindset achievement through teacher professional development (pd) days and closer engagement between schools and aina-based education organi | $150,000 | apps.irs.gov | |
| Hawaii Conservation Alliance Foundation | Honolulu, HI | For the next phase of the ahupuaa accelerator, a program to expand watershed-wide community management that has expanded to 46 partners statewide. [6153; pc] | $132,715 | apps.irs.gov | |
| Resources Legacy Fund | Sacramento, CA | To help advance the holomua initiative and the care for aina now coalition (formerly green fee) environmental capital formation work [6125; pc] | Environment | $120,000 | apps.irs.gov |
| The American Ai Forum Aka Ai Education Project | San Francisco, CA | To deliver professional development that helps hawaii public school teachers better understand artificial intelligence (ai) and how to responsibly incorporate ai literacy into their curriculum. [6286; | $115,000 | apps.irs.gov | |
| College Summit Inc Dba Peerforward | Washington, DC | To scale a promising peer counseling model to four additional high schools. [6267; pc] | $103,163 | apps.irs.gov | |
| C&C of Honolulu Office of Climate Change Sustainability and Resiliency | Honolulu, HI | To help the honolulu city & county optimize its climate adaptation work aligned with the foundation's new climate strategy [5860; gov] | $100,000 | apps.irs.gov | |
| Hawaiian Islands Land Trust (hilt) | Honolulu, HI | To continue to work in close partnership with the trust for public lands to secure priority lands for community use and aina aloha mindset development in windward oahu. [6259; pc] | $100,000 | apps.irs.gov | |
| New Teacher Center | Santa Cruz, CA | To work alongside the hawaii department of education in building the support and resources that enable complex area leaders to bring effective mathematics coaching to their school communities [6372; p | $100,000 | apps.irs.gov | |
| Conservation International Foundation | Honolulu, HI | Puulau project: a two-year effort to combine additional knowledge bases from fishers and community with wester-science based monitoring data to improve participation and decision making for the holomu | $95,000 | apps.irs.gov | |
| Koolau Foundation | Kaneohe, HI | Catalyst funding to develop the haiku valley cultural preserve [5907; pc] | $75,000 | apps.irs.gov | |
| Kualoa-Heeia Ecumenical Youth Project (key) | Kaneohe, HI | To bolster response to the little fire ant in koolauloa and koolaupoko through grassroots community education, training, monitoring, and response [6133; pc] | $75,000 | apps.irs.gov | |
| The Pacific American Foundation (paf) | Kaneohe, HI | For the launch of an esports development program in windward oahu schools [6127; pc] | $75,000 | apps.irs.gov | |
| College Summit Inc Dba Peerforward | Washington, DC | Peers leading peers through higher education [5516; pc] | $70,000 | apps.irs.gov | |
| 50can | Washington, DC | Core organizational support for hawaiikidscan, an education advocacy organization committed to ensure that hawaii has an excellent and equitable education system [5898; pc] | Education | $67,500 | apps.irs.gov |
| Public Schools Hawaii Foundation | Honolulu, HI | To launch a new effort that combines human and artificial intelligence to expand student support by offering more personalized navigational guidance and improving academic performance through targeted | Education | $67,500 | apps.irs.gov |
| Center for Tomorrow's Leaders | Honolulu, HI | To strengthen the persuasive communication and writing of the roughly 300 high school students served each year [6368; pc] | $60,000 | apps.irs.gov | |
| Hawaii Alliance of Nonprofit Organizations | Honolulu, HI | To help nonprofits engage in policy, work with data to develop clearer outcomes, and develop stronger revenue streams [6378; pc] | Community improvement and capacity building | $60,000 | apps.irs.gov |
| Hawaii Chamber of Commerce Foundation | Honolulu, HI | To support employer collaboratives that help ensure students in hawaii are on clear pathways to high skill, high wage, in-demand careers and that help hawaii businesses have a highly skilled, local ta | $60,000 | apps.irs.gov | |
| Hawaii Workforce Pipeline | Kailua, HI | To forge stronger connections between windward employers and public school students in the region. [6282; pc] | Education | $55,340 | apps.irs.gov |
| Collaborative Support Services | Honolulu, HI | General operating support for the commit to keiki initiative to educate candidates and elected officials about the importance of investing in early childhood development [6377; pc] | $50,000 | apps.irs.gov | |
| Collaborative Support Services | Honolulu, HI | Building a community-based early childhood continuum in the waimnalo community of oahu [5605; pc] | $50,000 | apps.irs.gov | |
| Hawaii Chamber of Commerce Foundation | Honolulu, HI | Unsolicited challenge grant to hawaii chamber of commerce foundation to support business relief fund to help businesses affected by the maui wildfires [5953; pc] | $50,000 | apps.irs.gov | |
| Hawaii Community Foundation (HCF) | Honolulu, HI | Support to ensure appropriate administration of the maui strong fund's current and expected grant expenditures totaling $192.6 million in a way that optimizes impact and transparency in the four phase | $50,000 | apps.irs.gov | |
| Hawaii Executive Collaborative | Honolulu, HI | Support for the rediscovering hawaii's soul initiative to create spaces where leaders from all sectors could have candid, difficult discussions to work together to take action that will create a bette | Community improvement and capacity building | $50,000 | apps.irs.gov |
| Hui Malama O Ke Kai Foundation | Waimanalo, HI | E hoakoakoa: a community & educational space [5166; pc] | Arts, culture and humanities | $50,000 | apps.irs.gov |
| Leadership Instituue Hawaii Department of Education | Aiea, HI | Laying the foundation for middle level education magic:strengthening public middle schools in hawaii [5920; gov] | $50,000 | apps.irs.gov | |
| Manoa Heritage Center | Honolulu, HI | Sam cooke endowed fund [4463; pc] | Arts, culture and humanities | $50,000 | apps.irs.gov |
| Risehi Foundation | Kailua, HI | To support middle school youth in their development and career exploration. [6278; pc] | Arts, culture and humanities | $50,000 | apps.irs.gov |
| The Coral Reef Alliance | San Francisco, CA | To work with a coalition of partners to catalyze cesspool conversions at a meaningful scale sufficient to meet the states 2050 goal for 100% conversion. [6122; pc] | Environment | $50,000 | apps.irs.gov |
| The Nature Conservancy of Hawaii | Honolulu, HI | To continue their decades-long work with communities and the state on maui and hawaii island, as well as initiating new work on kauai [6329; pc] | $50,000 | apps.irs.gov | |
| Wastewater Alternatives and Innovations | Honolulu, HI | To lead state and non-profit partners in improving the way we manage water quality in hawaii as part of the holomua initiative [5854; pc] | $50,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | Develop a malama aina plan for moku o loe that grounds it in its cultural heritage and guides it through the changing climate ahead [5586; pc] | $49,335 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | To ensure each doe district has a strong regional intermediary partner for work-based learning and to build a new data and accountability system around the new statewide education attainment goal adop | $46,450 | apps.irs.gov | |
| Hawaii Electricians Training Fund | Honolulu, HI | Interim credential pre-apprenticeship program & recruitment expansion [6065; nc] | $40,000 | apps.irs.gov | |
| Hi Fusioned (isis Hawaii) | Honolulu, HI | To move key elements of coding education and career pipelines forward, including teacher training and career exposure/mentorship, specifically targeting elementary and middle schools [5744; pc] | $40,000 | apps.irs.gov | |
| Project Vision Hawaii | Honolulu, HI | To provide free hearing screenings for youth as a complement to project vision hawaii's already successful vision screening program, support the transition from private funding to public reimbursement | Medical research | $40,000 | apps.irs.gov |
| River of Life Mission | Honolulu, HI | Support to strengthen and expand river of life's new distributed hub model of serving windward oahu's homeless population to transition them off the streets using a systemic approach, trained voluntee | $40,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | Honolulu community college (honcc) summer cte academy (2024, 2025) [6021; pc] | $40,000 | apps.irs.gov | |
| Vibrant Hawaii | Hilo, HI | To develop a network of resilience hubs across windward oahu [6275: pc] | Community improvement and capacity building | $40,000 | apps.irs.gov |
| Malama Learning Center Corp | Honolulu, HI | To produce another eight segments for local popular cable show outside hawaii that humanizes dlnr and socializes the intentions and actions of the holomua initiative [6367;pc] | Education | $31,500 | apps.irs.gov |
| Hawaii Department of Education Ocid-Extended Learning Branch | Honolulu, HI | Support for hawaii department of education complex area teams to coordinate student-led student transition activities to and from middle school [6347; gov] | $30,000 | apps.irs.gov | |
| College Promise | Washington, DC | To review and provide feedback on the hawaii promise initiative [6252; pc] | $25,000 | apps.irs.gov | |
| Hawaii Afterschool Alliance | Honolulu, HI | To support a developmental evaluation of the community schools model in twelve participating public schools [5870; pc] | $25,000 | apps.irs.gov | |
| Hawaii Executive Collaborative | Honolulu, HI | Support of 2024 hawaii executive conference [6385; pc] | Community improvement and capacity building | $25,000 | apps.irs.gov |
| Hawaii Local2030 Hub | Honolulu, HI | To allow hawaii green growth to continue to populate the state's 2030 sustainability goals dashboard and to spur action to achieve these goals [6137; pc] | $25,000 | apps.irs.gov | |
| Hawaii Workforce Funders Collaborative | Kapaau, HI | For the hawaii workforce funders collaborative (hwfc) to cover membership dues that support the operative budget of this new organization that supports effective workforce development across the state | Employment | $25,000 | apps.irs.gov |
| KHM International | Kaunakakai, HI | Malama e lua loko i'a: support for ka honua momona to restore their two adjacent fishponds on moloka'i with priority on the makaha of ali'i fishpond [5667;pc] | Environment | $25,000 | apps.irs.gov |
| Kanu Hawaii | Honolulu, HI | Pledge to our keiki: a tie-off grant to help kanu hawaii build on the pledge to our keiki platform to cement its department of education collaboration, strengthen its engagement with corporate sponsor | Environment | $25,000 | apps.irs.gov |
| Malama Maunalua | Honolulu, HI | To help advance the holomua initiative by better aligning pro-fishing perspectives with those of government agencies, community groups, and environmental organizations. [6126; pc] | Environment | $25,000 | apps.irs.gov |
| Oahu Resource Conservation and Development Council | Kunia, HI | To support strategic and sustainability planning for pop-ups labs for steam (puls) [6095; pc] | Environment | $25,000 | apps.irs.gov |
| Paepae O Heeia | Kaneohe, HI | Serving as fiscal sponsor for koolau aina aloha, to support their collective impact goals and specifically support the second phase of their aina aloha mindset competency pilot in close coordination w | Human services | $25,000 | apps.irs.gov |
| Residential Youth Services & Empowerment | Kailua, HI | To support their drop-in shelter and services for youth ages 14-24 [5637; pc] | $25,000 | apps.irs.gov | |
| Sustainable Coastlines Hawaii | Honolulu, HI | To help establish a "solutions center" in kahuku as a center for ocean plastics education and recycling and an aina-based education site [6067; pc] | Environment | $25,000 | apps.irs.gov |
| The Pacific American Foundation (paf) | Kaneohe, HI | To support the kilo kai program, providing ocean-related stem pathways for young people attending public high schools in the koolau region of oahu. [6326; pc] | $25,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | Core operating support that allows the uh economic research organization to more effectively engage with decisionmakers on important policy decisions facing our community [5847; pc] | $25,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | Support to increase retention of students at windward community college and strengthen the relationships between students and faculty, along with strengthening the relationships between instructional | $23,740 | apps.irs.gov | |
| Boys & Girls Club of Hawaii | Honolulu, HI | Own your own future initiative: whats next initiative parent engagement [5728; pc] | $20,000 | apps.irs.gov | |
| Healthy Climate Communities | Kailua, HI | To continue efforts to restore hamakua marsh with native flora so that native waterfowl use of the area increases. funds will help the organization grow programmatic offerings, volunteer and donor bas | Environment | $20,000 | apps.irs.gov |
| Iolani School Ka'i Program | Honolulu, HI | Own your own future initiative: 'iolani school ka'i program: family engagement & vocational learning opportunities [5736; pc] | $20,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | Own your own future initiative: kupu o ke koolau - kaikuaana/kaikaina mentorship program [5811; pc] | $20,000 | apps.irs.gov | |
| James B Castle High School | Kaneohe, HI | Own your own future initiative: differentiating the chs work-based learning continuum to meet the aspirations of all students [5734; gov] | $17,932 | apps.irs.gov | |
| Hilo High School | Hilo, HI | Support for post-high student transitions [6447; gov] | $15,000 | apps.irs.gov | |
| Kailua High School | Kailua, HI | Support for post-high student transitions [6451; gov] | $15,000 | apps.irs.gov | |
| Kapolei High School | Kapolei, HI | Support for post-high student transitions - huakai pono: guiding kapolei's youth toward their future [6454; gov] | $15,000 | apps.irs.gov | |
| Kealakehe High School | Kailua Kona, HI | Support for post-high student transitions and stronger senior capstone projects [6475; gov] | $15,000 | apps.irs.gov | |
| Molokai High and Intermediate School | Hoolehua, HI | Support for post-high student transitions [6448; gov] | $15,000 | apps.irs.gov | |
| Seeqs Foundation | Honolulu, HI | A one-time grant in support of seeqs public charter school to establish the "seeqs sharing hub" as a center of professional development and community connection. [6406;pc] | Education | $15,000 | apps.irs.gov |
| Waikea High School | Hilo, HI | Support for post-high student transitions for waiakea graduates [6465; gov] | $15,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | Investing in teachers, honoring student voices: the hawaii writing project young writers camp [pc; 6243] | $12,500 | apps.irs.gov | |
| Department of Education Windward District | Kaneohe, HI | Own your own future initiative: the wayfinder project - waimanalo and kailua high families successfully navigating college and career pathways [5786; gov] | $10,000 | apps.irs.gov | |
| Hawaii Association of Independent Schools | Honolulu, HI | To the hawaii association of independent schools to support an executive search process [6265; pc] | Education | $10,000 | apps.irs.gov |
| Hawaii Community Foundation (HCF) | Honolulu, HI | To honor four pilina fund community members by making a gift to a nonprofit recipient of their choosing [6497; pc] | $10,000 | apps.irs.gov | |
| Kohala High School | Kapaau, HI | Own your own future initiative: it takes a village project [5813; gov] | $10,000 | apps.irs.gov | |
| Malama Learning Center Corp | Honolulu, HI | Marine management mo'olelo: expanding public support of holomua: marine 30x30 through story-telling about the people of hawai`i dlnr-dar and docare [5501; pc] | Education | $10,000 | apps.irs.gov |
| Nurture Cultivate Inc | Honolulu, HI | For support of a new koolauloa aina-based education program in hauula, oahu [5831; pc] | $10,000 | apps.irs.gov | |
| Ka'u High and Pahala Elementary School | Pahala, HI | Ka'u high & pahala elementary school and naalehu elementary school transition partnership [6217; gov] | $7,500 | apps.irs.gov | |
| Kula Elementary School Pta | Kula, HI | Kula-kalama middle school transition [6214; pc] | $7,500 | apps.irs.gov | |
| Moanalua Middle School | Honolulu, HI | Moanalua middle school 6th grade transition [6208; gov] | $7,500 | apps.irs.gov | |
| Pahoa High & Intermediate School | Pahoa, HI | Pahoa high and intermediate school middle school academy collaboration [6168; gov] | $7,500 | apps.irs.gov | |
| West Hawaii Complex Area | Kailua Kona, HI | West hawaii middle school to high school academy transition planning [6218; gov] | $7,500 | apps.irs.gov | |
| Bottles4college | Hauula, HI | Wylf youth grant: bottles4college [5956; pc] | Education | $5,000 | apps.irs.gov |
| Boys & Girls Club of Hawaii | Honolulu, HI | For an unsolicited grant award to windward boys and girls clubhouse [6130; pc] | $5,000 | apps.irs.gov | |
| Boys To Men Mentoring Network of Hawaii Incorporated | Kamuela, HI | To support expansion of boys to men hawaii (btmh) programs on hawai'i island, maui and kauai [5938; pc] | Youth development | $5,000 | apps.irs.gov |
| James B Castle High School for Castle Performing Arts Center | Kaneohe, HI | Wylf youth grant: castle kids story time [6087; gov] | $5,000 | apps.irs.gov | |
| Kailua Historical Society | Kailua, HI | Unsolicited grant to kailua historical society in recognition of our longstanding commitment to kailua and to honor the memory of dr. paul brennan [6121; nc] | $5,000 | apps.irs.gov | |
| Kalaheo High School | Kailua, HI | To strengthen the quality of their natural resource pathway [6093; gov] | $5,000 | apps.irs.gov | |
| Kalaheo High School | Kailua, HI | Kalaheo class of 2024 project grad [6164;pc] | $5,000 | apps.irs.gov | |
| Kauai Economic Development Board | Lihue, HI | To develop high-quality island-wide advisory boards that support area high schools and the related career academies [6084; pc] | $5,000 | apps.irs.gov | |
| Malama Honua Public Charter School Foundation | Waimanalo, HI | Wylf youth grant: ko kakou kuleana [6011; pc] | Education | $5,000 | apps.irs.gov |
| Malama Honua Public Charter School Foundation | Waimanalo, HI | Wylf youth grant: malama honua pcs papa hula - malama aina [6124; pc] | Education | $5,000 | apps.irs.gov |
| The Chamber of Commerce of Hawaii | Honolulu, HI | To support campbell complex middle school to career alignment through sector partnerships [6091; pc] | $5,000 | apps.irs.gov | |
| University of Hawaii Foundation | Honolulu, HI | To support the right to read: film screening & discussion, as part of the uh better tomorrow speaker series, to raise awareness about improving literacy education based in science in hawaii. [6352; pc | $5,000 | apps.irs.gov | |
| Inspire International | Waipahu, HI | To match an employee contribution [6484; pc] | Religion-related | $2,500 | apps.irs.gov |
| Lutheran Church Missouri Synod | Kaneohe, HI | Wylf youth grant: malama 'aina - supporting our kupuna [6108; pc] | $1,800 | apps.irs.gov | |
| After-School All-Stars Hawaii | Honolulu, HI | To match an employee contribution [6355; pc] | Human services | $500 | apps.irs.gov |
Causes funded
From grants whose recipient has a cause.
| Cause | Granted |
|---|---|
| Environment | $315,000 |
| Education | $271,840 |
| Community improvement and capacity building | $175,000 |
| Arts, culture and humanities | $150,000 |
| Medical research | $40,000 |
| Human services | $25,500 |
| Employment | $25,000 |
| Youth development | $5,000 |
States funded
| Recipient state | Granted |
|---|---|
| Hawaii | $5,502,838 |
| California | $935,000 |
| District of Columbia | $265,663 |
Also on SpecStream
- Who funds education in Hawaii
- Who funds community improvement and capacity building in Hawaii
- Who funds environment in California
- Who funds arts, culture and humanities in Hawaii
- Who funds environment in Hawaii
- Who funds education in District of Columbia
Updated November 13, 2025. Read from IRS Form 990-PF e-file data. Public domain (U.S. government work). Grants are as each foundation reported them to the IRS on its Form 990-PF. Grants to individuals are left out. A grant has a cause only where the recipient's name and city match one organization in the IRS Business Master File, and the cause is that organization's NTEE major group. Free to reuse with credit to SpecStream under CC BY 4.0. Spot a wrong value? Write to [email protected] with the link to this page.