Oz is a realm featured on ABC's Once Upon a Time. Oz is divided into the north, the east, the west and the south, as well as the Emerald City, which is the capitol that resides at Oz's center. Its ruler was the Wizard of Oz, until the Wicked Witch of the West overthrew him and took over.
- Based on the Land of Oz that appears in The Wonderful Wizard of Oz.
- S1, E17: "Hat Trick" (portal)
- S3, E16: "It's Not Easy Being Green" (flashback)
- S3, E20: "Kansas" (flashback)
- S4, E17: "Heart Of Gold" (flashback)
- S5, E16: "Our Decay" (flashback)
- S5. E18: "Ruby Slippers"
- S5, E19: "Sisters" (flashback)
- S6, E18: "Where Bluebirds Fly" (flashback)
- S6, E20: "The Song in Your Heart" (flashback)
- S6, E21: "The Final Battle, Part One" (portal)
- S6, E22: "The Final Battle, Part Two" (portal)