Katherine Kelly Lang was born on July 25, 1961. She is an American actress, best known as Brooke Logan on the American daytime soap opera The Bold and the Beautiful.

Lang was born Katherine Kelly Wegeman in Hollywood, California; she graduated from Beverly Hills High School. Lang is the daughter of Olympic ski-jumper Keith R. Wegeman and actress Judith Lang and the granddaughter of Oscar-winning cinematographer Charles Lang.

Her first credit was a movie called Skatetown, U.S.A. (1979), with Scott Baio, Mark Hamill, and Patrick Swayze. That was followed by guest roles in various television series such as the short-lived The Powers of Matthew Star and Masquerade and the longer-running Riptide, Happy Days, The Fall Guy, and HBO's 1st & Ten.She also did a soft core porn 1996 called "Subliminal Seduction" with Ian Ziering of 90210.Lang as Brooke Logan.

In 1987, Katherine was offered the part of middle-class Brooke Logan on the soap opera The Bold and the Beautiful (B&B), and has been an integral part of the program ever since. Her love affair with Ridge Forrester (played by Ronn Moss) has been a key story arc for over 20 years, and a love triangle among Brooke, Ridge, and Taylor (Hunter Tylo) stretched across an entire decade. The show's 5,000th episode included only four characters: Brooke, Ridge, Stephanie and Eric.

Katherine appeared as her character, Brooke Logan on B&B's sister show, The Young and the Restless in 1998. She interacted with Eric Braeden (Victor), Peter Bergman (Jack), and Eileen Davidson (Ashley). She previously appeared on Y&R as Gretchen in 1981. She returned to Y&R in July 2007 for a brief stint as Brooke.

Her work on B&B has been recognized with seven Soap Opera Digest Award nominations, beginning in 1991 and most recently in 2005.