Tir Nan Og is the realm of the Earth fairies. It is an island located in the ocean to the west of Ireland and is not found on any ordinary map. When the four Wizards of the Black Circle captured the Earth fairies, they imprisoned them in their own kingdom of Tir Nan Og, where most of the terrestrial fairies remained until Roxy and the Winx freed them in Episode 95, The Enchanted Island, using the White Circle, which is the only key to the realm of the Earth fairies. The realms name refers to the island of Tír na nÓg from Irish myths and legends.
Morgana is the former Queen of the Earth Fairies, Rick's wife and Roxy's mother. After the Winx freed the Earth fairies she led the Earth fairies' revenge against the Wizards of the Black Circle for imprisoning them, and against the humans for stopping to believe in them and for damaging nature. At the end, she abdicated her Earth fairy throne and went to live with her husband and daughter in Gardenia. She was possibly inspired by Morgan le Fay from the Arthurian legend. She is voiced by Mindy Sterling in the Nickelodeon dub.
Queen Nebula was one of the majorly powerful terrestrial fairies trapped within the mystical White Circle and Morgana's second in command. She used to be the fairy of peace, but was turned into the fairy of war by her intense rage and vengeance against both humans and the Fairy Hunters. At the end of the fourth season she finally lets go of her anger and becomes the new Queen of the Earth fairies after Morgana abdicates. She is voiced by Karen Strassman in the Nickelodeon dub.
Diana is the major fairy of nature. She lives in the Amazon Forest with the Amazon fairies. She is voiced by Tara Strong in the Nickelodeon dub.
Aurora is the major Earth fairy of the North. She lives in a floating ice palace called the Ice Tower. She possesses incredibly powerful cryokinetic abilities over ice, hail, frost, and snow. Her followers are the Arctic fairies. She is voiced by Megan Goldsmith in the Nickelodeon dub.
Sibylla is the fairy of justice. She escaped from Tir Nan Og and she lives in a cave located in the Sibillini Mountains in Italy, named after her, along with her followers, the Rustic fairies. She is voiced by Laraine Newman in the Nickelodeon dub.