Sofia G. as Jackie Sky- Jackie is generally known to be very sensitive and thoughtful. She is caring, nice, normally very happy and calm. Jackie is sometimes the peacemaker and the solver when ever Selena and Emily fight, which she can't stand when they do. She has the power to heat water from warm to boiling in millions of seconds. She also has the power of telekinesis, to control objects with the mind without touching it. Sofia appears in all series of the show.
Marlena L. as Selena White- Selena is known as funny and very caring. She is the youngest out of the three. At times Selena tends to be very playful when ever the girls are in trouble or not. But throughout the series she matures. She has the power to make objects disappear with her mind and later gets the power of freezing water. Marlena appears in all series of the show.
Natasha G. as Emily Emery- Emily is the new girl at the start of the show. Emily can be known as a person of her word. When she says something she literally means it. Sometimes she can have quite a temper but not often. She is usually very friendly and snaps at people when ever they have an attitude. She has the power to make objects fly and later gets the ability to control and manipulate water. Natasha appears in all series of the show.
Ruby R. as Mia- Mia is mean, snobby, and most of the time selfish. But most of that changed when she became a mermaid. She ask the girls for help about being a mermaid but they rejected her. After being around them she became more friendly. In the third season Mia says she isn't who she said she was. Meaning that her real name may not be Mia and probably pretended to be the girls friends. She has the power to break things with her mind.