Danny DeVito as The Lorax (voice)

Ed Helms as Once-ler (voice)

Zac Efron as Ted Wiggins (voice)

Rob Riggle as Mr. Aloysius O'Hare (voice)

Taylor Swift as Audrey (voice)

Jenny Slate as Mrs. Wiggins (voice)

Betty White as Grammy Norma (voice)

Nasim Pedrad as Once-ler's Mom (voice)

Joel Swetow as 1st Marketing Guy (voice)

Michael Beattie as 2nd Marketing Guy (voice)

Elmarie Wendel as Aunt Grizelda (voice)

Dave B. Mitchell as 1st Commercial Guy (voice)

Dempsey Pappion as 2nd Commercial Guy (voice)

Danny Cooksey as Brett / Chet (voice)

Stephen Tobolowsky as Uncle Ubb (voice)

Chris Renaud as Forest Animals (voice)

Sherry Lynn as Additional Voices (voice)

Mickie McGowan as Additional Voices (voice)

Jack Angel as Additional Voices (voice)

Bob Bergen as Additional Voices (voice)

Debi Derryberry as Additional Voices (voice)

Danny Mann as Additional Voices (voice)

Fletcher Sheridan as Cy (voice)

John Cygan as Additional Voices (voice)

Bill Farmer as Additional Voices (voice)

Jess Harnell as Additional Voices (voice)

Mona Marshall as Additional Voices (voice)

Laraine Newman as Additional Voices (voice)

Jan Rabson as Additional Voices (voice)

Claira Nicole Titman as Additional Voices (voice)

Jim Ward as Additional Voices (voice)