Gregory "Greg" Sumner is a fictional character from the CBS soap opera Knots Landing, a long-running serial about middle class life on the fictional cul-de-sac known as Seaview Circle in Los Angeles, California. He was played by actor William Devane between 1983 and 1993. He debuted in the fourth episode of the fifth season. Devane remained a principal actor in the series until the final episode.