Richard Kuen Loo (October 1, 1903 – November 20, 1983) was an American actor. He was one of the most familiar Asian American character actors during the Golden Age of Hollywood, appearing in numerous films of the 1930s through the 1950s. Though of Chinese ancestry, he often portrayed villainous Imperial Japanese military officers during the Second World War. Later in his career, he was active mainly on television.

Loo was born in Maui, Hawaii in 1903. He was a third-generation Chinese American, of Hakka ancestry. After spending his youth in Hawaii, he moved to California as a teenager. He studied business at the University of California at Berkeley, and upon graduating he opened a successful import-export company in the San Francisco Bay Area. However, the 1929 stock market crash and the subsequent Great Depression prematurely ended his business career.

Loo became involved in amateur theatre productions in San Francisco, and later took up drama classes at Pearl S. Buck’s East and West Association in Chinatown. After turning professional, he moved to Hollywood to appear at the Pasadena Playhouse, and made his film debut in 1931.

Like most East Asian actors in Hollywood, Loo typically played small, stereotypical roles, though he rose quickly to familiarity, if not fame, in a number of films. One of his earliest prominent roles was as a treacherous antagonist in the 1933 pre-Code film The Bitter Tea of General Yen, directed by Frank Capra, which was singled out by columnist Louella Parsons. However, the lack of strong roles for minority actors in Hollywood meant that he was largely relegated to minor parts (many uncredited) until the outbreak of World War II. He was considered an "atmosphere" player along with Spencer Chan and Willie Fung, and served on the Screen Actors Guild's Racial Committee.

Loo’s stern features, sly grin, and sharp voice led him to be a favorite movie villain, and US entry into the war (along with the internment of any actual Japanese actors) gave him greater prominence in roles as vicious Japanese soldiers in such successful pictures as The Purple Heart (1944) and God Is My Co-Pilot (1945). In The Purple Heart, he plays a Japanese Imperial Army general who commits suicide because he cannot break down the American prisoners. According to his daughter, Beverly Jane Loo, the actor (who had been deferred from military service due to health issues) didn't mind being typecast as a villain in these movies as he felt very patriotic about playing those parts. In many of these films, he appeared alongside the Korean American actor and activist Philip Ahn.

Loo did also play more heroic characters. In 1944, he played a Chinese army lieutenant opposite Gregory Peck in The Keys of the Kingdom. In 1951, he played a war-weary Japanese-American soldier in Samuel Fuller's Korean War classic The Steel Helmet. However, he spent much of the latter part of his career performing stock roles in films and minor television roles. He also appeared in the hit Broadway plays South Pacific and The Teahouse of the August Moon.

In 1974, he played the supporting villain Hai Fat in the James Bond film The Man with the Golden Gun, opposite Roger Moore and Christopher Lee.

Loo was also a teacher of Shaolin monks in three episodes of the 1972–1975 hit TV series Kung Fu and made a further three appearances as a different character. His last acting appearance was in The Incredible Hulk TV series in 1981, but he continued to act in Toyota commercials into the following year.