Bennett received star billing in the gothic soap opera "Dark Shadows" for its entire five-year run, 1966 to 1971, receiving an Emmy Award nomination in 1968 for her performance as Elizabeth Collins Stoddard, mistress of the haunted Collinwood Mansion. Her other roles in "Dark Shadows" were Naomi Collins, Judith Collins Trask, Elizabeth Collins Stoddard PT (parallel time, as the show described its alternate reality), Flora Collins, and Flora Collins PT. In 1970, she appeared as Elizabeth in "House of Dark Shadows", the feature film adaptation of the series. However, she declined to appear in the sequel "Night of Dark Shadows", and her character Elizabeth was mentioned therein as being recently deceased.