Abby Fairgate (formerly Cunningham, Ewing and Sumner) is a fictional character from the CBS prime time soap opera Knots Landing. Abby's storylines focused on business dealings, affairs and family troubles. Introduced as the sister of Sid Fairgate, she was initially portrayed as a friendly, warm-hearted woman with great love for her children. In due time, she evolved into the series' main antagonist, constantly causing mayhem in others' lives.