Katherine Mayfair (formerly Davis) is a character created by Marc Cherry for the ABC television series Desperate Housewives. The character was portrayed by Dana Delany and first appeared in the series' fourth season premiere on September 30, 2007, as the focus of the yearly mystery.
Katherine is generally characterized by her cold demeanor and impressive domestic skills. Though initially a homemaker, Katherine started a catering business with neighbor Bree Van de Kamp (Marcia Cross), with whom she shares "a heated rivalry." She has been married twice, to Wayne Davis (Gary Cole) and Adam Mayfair (Nathan Fillion), but both relationships ended in divorce. Katherine has had two children; Dylan Davis (Hailee Denham), her daughter who died as a young child, and Dylan Mayfair (Lyndsy Fonseca), her adoptive daughter. The character was later paired with Mike Delfino (James Denton) in the fifth season, which later ended when he returned to and remarried Susan Mayer (Teri Hatcher). The series' sixth season saw Katherine written into the series' first lesbian relationship with Robin Gallagher (Julie Benz), which attracted media attention. Delany left the series soon thereafter, when the character relocated to Paris indefinitely with Robin. Delany returned for a guest appearance during the series finale of Desperate Housewives in 2012.
When Katherine was introduced to the series, many critics noted that she was very similar to Bree Hodge (Marcia Cross), in that both prided themselves on their domestic skills. Cherry noted that Katherine "was clearly different" before her arrival in the fourth season, which Susan confirms when she claims Katherine is "not as fun as she used to be." Her cold exterior is noted by many characters, including Gabrielle Solis (Eva Longoria Parker), who remarks that Katherine is "smug and 'holier than thou'" and is "getting a reputation around [the neighborhood] for having a stick up [her] ass!" Though Katherine immediately conflicts with the other women on the street, most notably Bree, she eventually develops close friendships with her neighbors. Nevertheless, her rivalry with Bree continues but as a natural part of their sisterly relationship. In the sixth season, however, Katherine "[morphs] into the person the housewives have to hate" in the absence of Edie Britt (Nicolette Sheridan). Katherine appears to be dependent on a romantic partner. Her first husband, Wayne, was abusive but she eventually left him and married Adam Mayfair. When he leaves, she tries convincing him to come home, saying that she is "lonely," despite having discovered that he had an affair. Later, in the fifth season, Katherine contemplates leaving Fairview because she is single, later revisiting the option in an attempt to force Mike to realize he loves her. She also resorts to trickery in order to ensure that Mike does not end their engagement. When Mike leaves Katherine for Susan, she suffers a complete nervous breakdown. When she becomes romantically involved with a woman, she puts her life in Fairview on hold indefinitely while trying to evaluate everything during an extended vacation in Paris.