- Dove Cameron as Liv and Maddie Rooney
- Joey Bragg as Joey Rooney
- Tenzing Norgay Trainor as Parker Rooney
- Kali Rocha as Karen Rooney
- Lauren Lindsey Donzis as Ruby
- Jessica Marie Garcia as Willow Cruz
- Shelby Wulfert as Maddie 2
- Emmy Buckner as Liv 2
- Chloe East as Val Wishart
- Jordan Fisher as Holden Dippledorf
- Victoria Moroles as Andie Bustamante
- Jimmy Bellinger as Artie Smalls
- Carter Hastings as Evan
- Laura Bell Bundy as TBA
- This is the first appearance of The Dream in the fourth season.
- Holden Dippledorf will make his first appearance in season 4 and the last because he will not be in the series finale End-A-Rooney, according to that episode's table read.
| To view the Voice-A-Rooney gallery, click here.