Kaahumanu Church, Protestant church in Wailuku, Hawaii, United States.

Kaahumanu Church is the fourth building on its Wailuku site, erected in 1875 in a simple New England Gothic style for the Wailuku Sugar Company manager Edward Bailey, honoring Queen Kaʻahumanu's request. The stone church measures 100 by 52 feet (30 by 16 m) over one floor and a gallery, and its bell and three clock faces came from the Seth-Thomas clock works in 1884.

The church was named after Queen Kaahumanu, who visited the original site in 1832 and asked the Congregationalist mission to honor her with the building's name. This request reflected the importance of the mission to local leadership and the growing connections between faith and the islands' rulers.

The services include hymns and invocations spoken in Hawaiian, keeping native traditions alive within the congregation's worship. This use of the native language during gatherings shows how the community honors its ancestral roots in their spiritual life.

The church holds regular services that are also available online through Facebook Live, making it possible to participate from a distance. Visitors should check current service times in advance and treat the building with respect as an active place of worship.

The Seth-Thomas clock and bell arrived in 1884, carried by ship around Cape Horn, and were donated by the Bailey family at a cost of $1,000. The clock has three faces, and Maui County officials named it the "Town Clock" of Wailuku in 1964.