One of the oldest school buildings in Hawaii that is still in use, Kawaiahao Hall was built to house Kawaiahao Seminary, which was established in 1864 as a boarding school for Hawaiian girls. Originally, the seminary was located across S. King Street from today's Mission Houses Museum (OA61). It was moved to this thirty-two-acre Manoa site in 1908, when it merged with Mills Institute, a boarding school for Chinese and, later, Japanese and Korean boys. The combined schools, both of which operated under the wings of the Hawaiian Evangelical Association, were renamed Mid-Pacific Institute.

The sturdy, three-story building with rusticated basalt walls stands on a raised foundation and presides over the campus from the top of a small rise. Its shed-roofed dormers and similarly roofed, chaletlike balconies root the building to the site. The first story is marked by a round-arched arcade, a portion of which is now enclosed. In 1981, the interior was gutted and revamped for contemporary scholastic needs. Originally, Kawaiahao Hall had a companion lava-rock structure, Wilcox Hall, which housed Mills Institute; it was destroyed by fire in 1950.