Glinda, the Good Witch of the South, pays a visit to Zelena and offers her a place in the Sisterhood of Witches. Zelena accepts, and becomes the Witch of the West. However, after a tornado carrying a house hits Oz, Glinda and Zelena discover a girl inside the house named Dorothy Gale. Zelena discovers that there is a prophecy in the Book of Records stating that a female who arrived in Oz by tornado will become the Witch of the West and vanquish the greatest evil Oz has ever seen. Zelena becomes jealous of Dorothy, and Glinda tries to comfort Zelena, saying that Dorothy will not take Zelena's place and that Zelena will not become evil unless she truly believes it. Zelena, however, confronts Dorothy at the well and tries to kill her with a fireball. Dorothy splashes Zelena with a bucket of water, causing Zelena to seemingly melt and die. Panicking, Dorothy calls for Glinda, and tells her what happened. Glinda doesn't blame Dorothy, saying that Zelena left her no choice. Believing that Zelena's magic will now be undone, Glinda takes Dorothy to the Wizard of Oz, who had been turned into a flying monkey by Zelena. It is revealed that Zelena faked her own death, and pretends to be the Wizard behind the curtain, giving Dorothy a pair of silver slippers which Dorothy uses to return back home to Kansas. After this, Zelena reveals herself to Glinda. Shocked, Glinda tries to reason with Zelena, but ends up banished to the Enchanted Forest.
Snow White and Prince David manage to find a door in the Enchanted Forest that leads to Glinda's snowy forest, a pocket dimension Glinda has retreated to, but only those with pure hearts may pass through it. Having to leave Regina behind, Snow and David visit Glinda and ask for her help to defeat Zelena. Glinda tells them that her magic has never been more powerful than Zelena, but instead tells them of the pendant that Zelena wears, revealing that it is what mainly holds her magic and revealing that if Zelena were to lose her pendant, she may be able to be defeated with light magic, which is magic made from love. Snow and David realize that they need their daughter Emma, who is the Saviour and the only person who can defeat Zelena with light magic.
- Zelena Mills (former "sister")
- Witch of the North (former "sister")
- Witch of the East (former "sister")
- She is based on Glinda the Good Witch of the South, from the story The Wonderful Wizard of Oz.
- Glinda wears a diamond pendant, which all four of the Witches of Oz wear. It stores their magical power, and if removed they will become powerless.
- Glinda represents the power and virtue of Love. Interestingly, each of the four ingredients of the time-travel spell that Zelena wishes to enact represents the virtues that the Sisterhood fuel their magic with. One of the ingredients for the spell is a resilient heart.
- S3, E19: "A Curious Thing" (flashback)
- S3, E20: "Kansas" (flashback)