Victor Sen Yung (born Victor Cheung Young or Sen Yew Cheung; Chinese: 森耀祥; October 18, 1915 – body discovered November 9, 1980) was an American character actor, best known for playing Jimmy Chan in the Charlie Chan films and Hop Sing in the western series Bonanza.

Sen Yung was born in San Francisco, California to Gum Yung Sen and his first wife, both immigrants from China. When his mother died during the flu epidemic of 1919, his father placed Victor and his younger sister, Rosemary, in a children's shelter, and returned to his homeland to seek another wife. He returned in 1922 with his new wife, Lovi Shee, once again forming a household with his two children.

Sen Yung made his first significant acting debut in the 1938 film Charlie Chan in Honolulu, as the Chinese detective's "number two son", Jimmy Chan. In this movie, Sidney Toler replaced the recently deceased Warner Oland as Charlie Chan and Sen Yung replaced Oland's "number one son" Lee, who had been played by Keye Luke. Luke left the series in 1938, leading to the need for a "number two son". Sen Yung played Jimmy Chan in 11 Charlie Chan films between 1938 and 1942. Sen Yung played the character of Jimmy Chan very much as Luke played Lee Chan, namely as the bumbling, Americanized son who constantly hinders his father's work. The cultural clash between Chan père, a Chinese immigrant whose values were fundamentally those of China as expressed in his amusing pseudo-Confucian aphorisms vs. his well meaning, but inept Americanized sons gave the series much of its appeal, together with the fact that for all of Charlie Chan's putdowns of his sons there was a genuine paternal love and warmth being expressed.

Moonlighting from the popular Chan series, Sen Yung won critical acclaim playing the nuanced role of Ong Chi Seng, a young attorney assisting Howard Joyce (played by James Stephenson), defending Leslie Crosbie (played by Bette Davis), accused of murder in the classic Warner Bros. film noir melodrama, The Letter (1940), directed by William Wyler. In common with other Chinese-American actors, Sen Yung was cast in Japanese parts during World War II, such as his role as the treacherous Japanese-American Joe Totsuiko in the 1942 Humphrey Bogart film Across the Pacific.

During World War II he joined the U.S. Army Air Forces just as his erstwhile co-star Sidney Toler was set to revive the dormant Charlie Chan series at Monogram Pictures. According to author James L. Neibaur, Sen Yung's military obligations forced him to decline rejoining the series immediately, but Monogram gave him a standing invitation to work there when his tour of duty was up. He was temporarily replaced in the Charlie Chan series by Benson Fong, who played "number three son" Tommy Chan (and once by Keye Luke's real-life brother, Edwin Luke, as "number four son" Eddie Chan). Sen Yung's military service included work in training films at the First Motion Picture Unit and a role in the Army Air Forces' play and film Winged Victory.

In 1946 Sen Yung resumed his Hollywood career at Monogram, now billed as Victor Sen Young and reunited with Sidney Toler. Toler's health was failing; Monogram was conserving Toler's waning energy, limiting his scenes and giving him long rest periods during filming. To relieve the burden on Toler, Monogram entrusted much of the action to Victor Sen Young; he and either Mantan Moreland or Willie Best shared much of the footage in Toler's final three films, Dangerous Money, Shadows Over Chinatown, and The Trap. The addition of Moreland as Chan's black chauffeur, Birmingham Brown, reflected the fact that by this time the Chan pictures had a significant following among black Americans, who liked a film series that for once did not feature a white hero. Moreland's popularity in the Chan pictures was so great that he was booked for a nationwide vaudeville tour, forcing him to be replaced in Dangerous Money by Willie Best.

Following Toler's death in 1947, Victor Sen Young appeared in five of the remaining six Charlie Chan features. His character "Jimmy" was renamed "Tommy" (author Scott MacGillivray contends that "Jimmy" was so closely associated with Sidney Toler that audiences would miss seeing Toler opposite him, resulting in Monogram making the change).

Arguably even more than for his work in the Charlie Chan films, Victor Sen Yung is well remembered as "Hop Sing," the irascible cook and general factotum on the iconic television series Bonanza, appearing in 107 episodes between 1959 and 1973. Bonanza series creator David Dortort told the Archive of American Television that the "Hop Sing" character generated massive fandom - "Victor was just absolutely delightful. He loved the part; he loved doing it. In fact, he began to develop fans, to the extent that I wrote him in as the featured part in a number of shows.”