James Bicknell Castle High School, more commonly James B. Castle High School or simply Castle High School, is a public coeducational high school located in Kāneʻohe CDP, City and County of Honolulu, Hawaiʻi. The school serves grades 9 through 12 and has an enrollment of around 1150 students. The school is part of the Windward Oʻahu Subdistrict of the Hawaii Department of Education.