Katherine Mayfair (Dana Delany) is an old friend of Susan Delfino (Teri Hatcher) who moved away from Wisteria Lane but returned years later. She does not get along with Bree Van De Kamp (Marcia Cross) because she upstaged Bree with her recipes. Katherine's daughter died in an accident so Katherine buried her and adopted a child from an orphanage to take her place so no one would find out. She begins a relationship with Susan's ex-husband Mike Delfino (James Denton) and is devastated when Mike leaves her to remarry Susan.

Katherine is committed after having a nervous breakdown. After she returns home, she begins an affair with an ex-stripper named Robin (Julie Benz). She leaves Wisteria Lane with Robin because she is afraid of what others will think about her having a lesbian relationship.

Memorable Quotes:

"We're the SAME, Bree. And if you think that means we can't be friends, then I'm sorry. But it might also mean we could be BEST friends."

"I tell you if I'm not careful this guy could steal my heart."