After the death of Lady Tremaine's husband, she and her daughters Clorinda and Tisbe treat Cinderella - the daughter of Lady Tremaine's husband - like a servant, making her do all of the chores and the housework while also being immensely cruel towards her. When they are finally invited to the royal ball, Lady Tremaine and her daughters have her dress burned and leave Cinderella behind. However, when Cinderella makes it to the ball anyway, Tremaine fools her into thinking that Prince Thomas is betrothed to Clorinda, when in reality Clorinda plans on eloping with the Prince's footman, Jacob. After finding this out from Cinderella herself, Lady Tremaine confronts Clorinda and attempts to murder Jacob until Cinderella intervenes. With her life not making any sense to her anymore, Lady Tremaine decides to flee to the Land of Untold Stories, dragging Clorinda along with her.
She and her daughters are briefly mentioned by Ruby, who says that Cinderella does not talk to them anymore.
Lady Tremaine and Clorinda are among those who travel to Storybrooke from the Land of Untold Stories. With the help of her own "fairy godmother" the Evil Queen, Tremaine seeks vengeance on those who ruined her chances of having one of her daughters rise in rank to royalty. Cinderella confronts Lady Tremaine, who in turn has Cinderella disarmed before she stabs her stepdaughter with the end of her cane. However, Emma Swan arrives shortly afterwards and magically heals Cinderella. Lady Tremaine is incarcerated for her crimes and forced to do community service. She is supervised by Grumpy the dwarf, who watches her as she picks up litter.
- Lord Tremaine (deceased first husband)
- Cinderella's father (deceased second husband)
- Clorinda Tremaine (daughter)
- Tisbe Tremaine (daughter)
- Cinderella (stepdaughter)
- Thomas Herman (stepson-in-law)
- Alexandra Herman (step granddaughter-in-law)
- She is based on the cruel and cunning stepmother from the fairytale Cinderella.
- Her weapon of choice is her cane, which has a sharpened end made of glass.
- Lady Tremaine is around fifty years old, having stated so in the Enchanted Forest.
- S1, E04: "The Price of Gold" (flashback)
- S6, E03: "The Other Shoe"