Keaʻau (also written as Keaau) is a census-designated place (CDP) in Hawaiʻi County, Hawaii.

[2] Keaau was called ‘Ōla‘a and in 1899, the Olaa Sugar Company leased about 4,000 acres of land, for growing sugarcane.

According to the United States Census Bureau, the CDP has a total area of 2.6 square miles (6.7 km2), all of it land.

[6] The Board on Geographic Names officially designated the populated place as Keaʻau in 2003.

The racial makeup of the CDP was 12.38% White, 0.22% African American, 0.18% American Indian & Alaska Native, 52.02% Asian, 7.50% Native Hawaiian & Pacific Islander, 0.44% from other races, and 27.25% from two or more races.