Karen MacKenzie is a long-running fictional character in the CBS primetime soap opera Knots Landing. Karen is portrayed by actress Michele Lee, and has appeared on the show since its pilot episode, first broadcast on December 27, 1979. Knots Landing follows the trials of four middle-class families living on a suburban cul-de-sac known as Seaview Circle in California. Lee portrayed Karen for the entire run of Knots Landing, being the sole cast member to appear in every episode of its fourteen seasons. At the time, her appearances in all 344 episodes set a record for an actress on American primetime television. Karen's storylines focus on family troubles, business dealings, addiction and kidnapping.

Knots Landing is an American primetime television soap opera that aired on CBS from December 27, 1979, to May 13, 1993. A spin-off of Dallas, it was set in a fictitious coastal suburb of Los Angeles and initially centered on the lives of four married couples living on a cul-de-sac, Seaview Circle. Throughout its 14-year run, storylines included marital strife, rape, murder, kidnapping, assassinations, drug smuggling, politics, environmental issues, corporate intrigue, and criminal investigations. By the time of its conclusion, it had become the third-longest-running primetime drama on U.S. television after Dallas, Gunsmoke, and Bonanza and the last scripted primetime drama show that debuted in the 1970s to leave the air.