Henry Ernest Cooper (August 28, 1857 – May 15, 1929) was an American lawyer who moved to the Kingdom of Hawaii and became prominent in Hawaiian politics in the 1890s. He formally deposed Queen Lili'uokalani of Hawaii in 1893, held various offices in the ensuing Provisional Government of Hawaii and Republic of Hawaii governments, and was the first United States Territory of Hawaii Attorney General, 1899–1900. He later became a circuit judge in Honolulu.