Katherine Mayfair (formerly known as Katherine Davis) is one of the supporting protagonists of Desperate Housewives, and thus her family is central to the series and its stories. They previously resided at 4356 Wisteria Lane.
- Katherine Mayfair - Katherine was married to an abusive cop, until she left him and her daughter died; Katherine replaced her daughter, and moved away from the lane, only to return 12 years later with a new husband in tow.
- Wayne Davis - Katherine's first husband, an abusive and alcoholic cop who beat her like crazy and held her hostage to find out what had happened to his daughter.
- Adam Mayfair - Katherine's second husband, a gynaecologist who was younger than her and who cheated on her, forcing them to move from Chicago to Wisteria Lane.
- Dylan Davis - Katherine's biological daughter, who was crushed under an armoir after trying to reach for a doll her daddy had brought her after her mother had put it up there; she was replaced by another girl.
- Dylan Mayfair - A young girl Katherine found in a Romanian orphanage, who was used to replace the real Dylan.
- Lillian Simms - Katherine's aunt, to whom she is very devoted, and who died without being able to tell her grand-niece about a terrible secret.
- Mr. Simms - Katherine's uncle and Lillian's husband.
- Mrs. Simms' son - The son of Lillian Simms, who visited Carlos Solis to let him know he couldn't stay in his mother's house any longer.
- Bradley and unnamed grandchild - Bradley is Dylan Mayfair's unseen husband, and together they have an unseen and unnamed kid, Katherine's grandchild.
- Robin Gallagher - Katherine's roommate after moving back to the lane from the mental hospital, and eventual gay lover; together, the two fled from the lane to Paris.
- Robin's Cat - Robin's pet cat that eats noodles and was the screensaver of her cell phone.
Note: Susan's family intertwines with Katherine's.