Mary Campbell (nee Gatling, previously Dallas) is one of the two principal characters on the serial-based situation comedy, Soap. She was played by the late actress, Cathryn Damon.
Mary is the sister of wealthy Jessica Tate. Some years before, she had married a mobster named Johnny Dallas, and through him had two sons, Danny, who was later discovered that his father was her later brother in-law, Chester Tate; and younger son, Jodie. She is also the grandmother of Jodie's young daughter, Wendy.
After Johnny's death, she fell in love with macho construction worker, Burt Campbell and married him. She became the stepmother of his two sons, randy tennis pro, Peter; and Chuck, a ventriloquist whose dummy, Bob, had nothing but contempt for the family.
Her closest relationship, though, is with her sister, Jessica. Half of her days are where she is hanging out with her, either talking in their homes, or going out to lunch. Mary couldn't live without her sister, and vice versa.
However, one secret nearly sundered their relationship. Mary had had an affair with Chester, which resulted in Danny's birth. Although she realized that Mary had no idea of what was going on between Chester's father and their mother, whom she was blackmailing the younger Tate to marry Jessica, for a time, Jessica would not speak to Mary.
Later on, though, Jessica forgave Mary and they were close again. Chester, however, was thrown out of both of their lives.
Mary would give birth to her fourth child (her first with Burt), named Scott Campbell. However, Scott's father was Alien Burt (the alien duplicate of Burt)! When Scott began to manifest the same powers that his alien father had, Mary became an alcoholic.
At first, Mary also did not forgive Burt for killing her first husband. However, he later revealed that he had killed Johnny in self-defense.