Other than Princess Aisha and Prince Nabu, the following characters are from planet Andros (renamed the Realm of Tides in the 4kids version).
King Teredor and Queen Niobe are the king and queen of the lands of Andros and the parents of Princess Aisha. King Teredor is also the brother of King Neptune. King Teredore is voiced by Obba Babatundé in the Nickelodeon dub. Queen Niobe is voiced by Grey DeLisle in the Nickelodeon dub.
King Neptune and Queen Ligea are mermen and the king and queen of the seas of Andros. They are also parents of Crown Prince Nereus, Prince Tritannus and Princess Tressa. King Neptune is also the brother of King Terador making him the uncle of Princess Aisha. King Neptune is voiced by Keythe Farley in the Nickelodeon dub. Queen Ligea is voiced by Laraine Newman in the Nickelodeon dub.
Crown Prince Nereus is the twin brother of Prince Tritannus. He is Aisha's cousin brother. Nereus is voiced by Will Friedle in the Nickelodeon dub.
Prince Tritannus is the twin brother of Crown Prince Nereus and very jealous of him as he did not get the throne. He is Aisha's cousin brother and the main villain in Season 5. He is voiced by Alberto Bognanni in the original version and by Adam Wylie in the Nickelodeon dub.
Princess Tressa is a mermaid and an ally to Winx. She is Aisha's cousin sister. She is voiced by Kether Donahue in the 4Kids version and by Laura Bailey in the Nickelodeon dub.
Anne is a childhood friend of Aisha. She appears in Aisha's flashbacks throughout Seasons 2 & 3. She is frequently mentioned by Aisha during Seasons 1,2,3 & 5.
Roy is a specialist who is ordered by King Teredor to sail a yacht for the Winx during their quest for Sirenix in season 5. He appears to have feelings for Aisha. Roy has a little magic himself, which he calls "Triton Aura". Roy has blond hair and dark grey eyes. He is voiced by Bryton James in the Nickelodeon dub.
Lemmy is the gatekeeper of ocean portal of Andros and Aisha's bonded selkie. She is voiced by Morgan Decker in the Nickelodeon dub.
Pyros is a realm populated by dragons. After Tecna was stuck in the Omega Dimension in the third season, Bloom went there to strengthen her powers in order to become strong enough to defeat Valtor.
Maia is an ascetic sorceress who lives on Pyros. She is an old friend of Ms. Faragonda.
Buddy is a dragon who lives on Pyros. When Bloom arrives there, Buddy teaches her how to act like a dragon, and Bloom also helps him to find his parents. Buddy is pale green with yellow wings. Compared to the other dragons that are seen on Pyros, he is very small. He is voiced by Sam Cohen in the Nickelodeon dub.
Omnia is the supreme guardian of Sirenix who grants the power of Sirenix to fairies who have completed the Sirenix quest and she invites the Winx and selkies to enter the infinite ocean after they complete their quest. She is voiced by Nika Futterman in the Nickelodeon dub.
The Guardian Selkies are selkies who guard the three Pillars of the Infinite Ocean that support the whole Magic Dimension, namely the Pillar of Light, the Pillar of Control and the Pillar of Balance.
The Golden Kingdom is a dimension where the Water Stars, which have the power opposite to that of the Dragon Flame, are kept. It is a place both outside and inside Time.
Arcadia is the first Fairy to have existed.
The Ancient Ones are the inhabitants of the Golden Kingdom. It is composed of Arcadia, a leprechaun-like creature, a mermaid-like being, a centaur and an owl-like creature. They have been living since the beginning of the Magic Dimension and they are guardians of the Water Stars.
The Ethereal Fairies are very powerful Fairies who live out of Time and Space. They appeared in Season 4 when they gave the Gifts of Destiny to the Winx and prophesied Nabu's death.