About Us

Founder & History

"We have long recognized the possibilities and the opportunity that is offered to plan and build for the future in this Ko‘olau area. Nature has placed in our hands every element necessary to construct a masterpiece – an inspiration and source of happiness that can enrich the lives of many generations to come. It can be realized only by the honest, unselfish and intelligent cooperation of every individual and organization who sincerely hopes to achieve this ultimate success. We certainly expect to do our part." -Harold K.L. Castle


Born in 1886, Harold Kainalu Long Castle was descended from successful Hawaii businessman, James Bicknell Castle, who was a partner of Castle & Cooke. Harold K.L. Castle purchased the title to 9,500 acres in the Kailua ahupua‘a in early 1917.

Realizing that the Windward side of the island of Oahu was a beautiful place to live and could become a vibrant community, Harold K.L. Castle and his wife Alice Hedemann Castle set out to do their part in building that community. Mr. Castle donated land for churches of all different denominations because he felt that churches would bring congregations, congregations would bring stability, and that would benefit the community that was growing around them. Mr. Castle also donated land and money to Hawaii Loa College, Castle Hospital, Iolani School, Castle High School and Kainalu Elementary School and the Mokapu peninsula land, which would become the Kaneohe Marine Corps Base.

The Harold K.L. Castle Foundation was founded in 1962 by Harold K.L. Castle. Upon his death in 1967, Mr. Castle bequeathed a sizeable portion of his real estate assets to the Foundation. These assets are the base from which the Foundation's grants are made. Harold Castle's son, James C. Castle, was a Director of the Foundation since its inception, and succeeded Harold Castle as President in 1968. He held this position until his death in 1994. In 1994, James C. McIntosh was elected President. James C. McIntosh is a grandson of Harold and Alice Castle, as was the late Director, John C. Baldwin.

The Foundation is the largest private foundation based in Hawaii. Each year the Directors award grants to nonprofit organizations benefiting the people of the State of Hawaii. Originally, grants focused on the Windward side of Oahu, youth, private education, arts and culture, and health care. The Foundation’s current investments are focused on public education redesign and enhancement, nearshore marine resource conservation, and strengthening the communities of Windward Oahu. Since its inception, the Harold K.L. Castle Foundation has awarded over $176 million in grants, with more than $60 million going to organizations serving Windward Oahu. Currently, the Foundation disburses an average of $6 million in grants per year.

Harold K.L. Castle Foundation - HOME