Wilma Jeanne Cooper (October 25, 1928 – May 8, 2013) was an American actress, best known for her role as Katherine Chancellor on the CBS soap opera The Young and the Restless (1973–2013). At the time of her death, she had played Katherine for nearly 40 years, and her name appears on the list of longest-serving soap opera actors in the United States. Cooper also appeared on numerous episodic television series in the 1950s and 1960s, as well as several film roles. She was the mother of three children, the eldest being actor Corbin Bernsen.