- Liv Rooney (Dove Cameron) is a former television star, who is the identical twin sister of Maddie.
- Maddie Rooney (Dove Cameron) is the star of her school's basketball team, who is the identical twin sister of Liv.
- Joey Rooney (Joey Bragg) is the younger brother of the Liv and Maddie and older brother of Parker.
- Parker Rooney (Tenzing Norgay Trainor) is the younger brother of the twins and youngest sibling in the Rooney family.
- Karen Rooney (Kali Rocha) is the mother of the four children and the school vice principal for her twin daughters' and Joey's school.
- Pete Rooney (Benjamin King) was a main character in Liv and Maddie and the father of Liv, Maddie, Joey and Parker and is also married to Karen Rooney. He was also the basketball coach for Maddie's basketball team at Ridgewood High. Pete doesn't appear in Season 4.
- Ruby (Lauren Lindsey Donzis) is the cousin of the Rooney's and lives in California with her mother.
- Diggie Smalls (Ryan McCartan) is the school's boys basketball team captain. He was Maddie's boyfriend in Move-A-Rooney, until they broke up in Flugelball-A-Rooney.
- Willow (Jessica Marie Garcia) is Maddie's friend. She is on Maddie's basketball team and has a huge crush on Joey.
- Skippy Ramirez (Allen Alvarado) is Joey's best friend. He is a professional skateboarder.
- Skylar (Gabrielle Elyse) is Joey's crush. In Kang-A-Rooney it shows she is new. She's friends with Joey.
- Artie (Jimmy Bellinger) is Joey's nemesis. He is a member of their school's rocketry club.
- Johnny Nimbus (Kurt Long) is the Channel 4 meteorologist and the host of the cooking segment "Nibblin' With Nimbus". He is a fan of Liv's ex-boyfriend, Miller White.
- Evan (Carter Hastings) is Parker's 9-years-old best friend and sidekick. Parker helped him earn his blue belt in their karate class.
- Gemma (Chloé Wepper) is the producer of Liv's new show, Voltage, in Season 3.
- Holden Dippledorf (Jordan Fisher) is the Rooney's neighbour and he becomes Liv's new boyfriend in Coach-A-Rooney.
- Josh Willcox (Lucas Adams) is Liv's co-star of Voltage in Season 3. He becomes Maddie's new boyfriend in Vive-La-Rooney.
- Aunt Dena (Jolie Jenkins) is the Aunt of the Rooney's, the mother of their cousin Ruby and the sister of Karen Rooney (the mother of the Rooney kids).
- Bernard (Dwight Howard) is a personal trainer who started working for Joey after he won a raffle. He joined Maddie's basketball team.
- Kylie (Anne Winters) is a bad girl who likes ditching school and shop-lifting. Liv wanted to be her friend, much to Maddie's dismay.
- Miller White (Connor Weil) is a professional skateboarder. He is Liv's ex-boyfriend.
- Jenny Keene (Ella Anderson) is a self-centered little girl who performed with Liv in the Stevens Point Holiday Spectacular.