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

Lang has been married and divorced twice, the second marriage to manager Alex D'Andrea. D'Andrea represents such actors as Stephen Baldwin and works for Edmonds Entertainment. Lang is the mother of three children: Jeremy Skott Snider (born 1990), Julian Lang Snider (born 1992), Zoe Katrina D'Andrea (born 1997) and stepdaughter Danyelle Puschendorf D'Andrea (born 1991). She is 5'-9" tall.

Lang's 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.

In 1985 Lang appeared in two music videos: Alabama's There's No Way (where she played the love interest of Alabama lead singer Randy Owen), and The Beach Boys' Getcha Back.

In 1987, she was offered the part of blue-collar 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 the four core characters: Brooke, Ridge, Stephanie and Eric.

She 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.