| Person | Type | Job | Role(s) |
|---|---|---|---|
 Audrey Geisel | Crew | Production | Executive Producer |
 Carter Goodrich | Crew | Visual Effects | Character Designer |
 Chris Renaud | Crew | Directing | Director |
 Chris Meledandri | Crew | Production | Producer |
 Cinco Paul | Crew | Production | Executive Producer, Writer, Songs, Screenplay |
 Dennis Leonard | Crew | Sound | Supervising Sound Editor |
 Dr. Seuss | Crew | Writing | Book |
 Gary Rizzo | Crew | Sound | Sound Re-Recording Mixer |
 John Powell | Crew | Sound | Original Music Composer, Songs |
 Ken Daurio | Crew | Production | Executive Producer, Writer, Screenplay |
 Ken Schretzmann | Crew | Editing | Editor |
 Kyle Balda | Crew | Directing | Co-Director |
 Randy Thom | Crew | Sound | Sound Designer, Sound Re-Recording Mixer, Supervising Sound Editor |
Steven Liu | Crew | Editing | Editor |
 Yarrow Cheney | Crew | Art | Production Design |
 Claire Dodgson | Crew | Editing | Editor |
 Fabrice Joubert | Crew | Visual Effects | Animation |
Catherine Catie Lee | Crew | Lighting | Lighting Artist |
 Eric Guillon | Crew | Visual Effects | Character Designer |
Mitja Rabar | Crew | Visual Effects | Animation |
Massimo Ruberto | Crew | Sound | Music Supervisor |
Janet Healey | Crew | Production | Producer |
 Betty White | Cast | Actress | Grammy Norma (voice) |
 Bill Farmer | Cast | Actor | Additional Voices (voice) |
 Bob Bergen | Cast | Actor | Additional Voices (voice) |
Chris Renaud | Cast | Actor | Forest Animals (voice) |
Danny Cooksey | Cast | Actor | Brett / Chet (voice) |
 Danny DeVito | Cast | Actor | The Lorax (voice) |
 Danny Mann | Cast | Actor | Additional Voices (voice) |
 Debi Derryberry | Cast | Actress | Additional Voices (voice) |
 Elmarie Wendel | Cast | Actress | Aunt Grizelda (voice) |
 Jack Angel | Cast | Actor | Additional Voices (voice) |
 Jess Harnell | Cast | Actor | Additional Voices (voice) |
 Jim Ward | Cast | Actor | Additional Voices (voice) |
 Joel Swetow | Cast | Actor | 1st Marketing Guy (voice) |
 John Cygan | Cast | Actor | Additional Voices (voice) |
 Laraine Newman | Cast | Actress | Additional Voices (voice) |
 Michael Beattie | Cast | Actor | 2nd Marketing Guy (voice) |
 Mickie McGowan | Cast | Actress | Additional Voices (voice) |
 Mona Marshall | Cast | Actress | Additional Voices (voice) |
 Sherry Lynn | Cast | Actress | Additional Voices (voice) |
 Stephen Tobolowsky | Cast | Actor | Uncle Ubb (voice) |
 Ed Helms | Cast | Actor | Once-ler (voice) |
 Nasim Pedrad | Cast | Actress | Once-ler's Mom (voice) |
 Rob Riggle | Cast | Actor | Mr. Aloysius O'Hare (voice) |
 Zac Efron | Cast | Actor | Ted Wiggins (voice) |
 Jenny Slate | Cast | Actress | Mrs. Wiggins (voice) |
 Taylor Swift | Cast | Actress | Audrey (voice) |
Claira Nicole Titman | Cast | Actress | Additional Voices (voice) |
 Jan Rabson | Cast | Actor | Additional Voices (voice) |
 Dempsey Pappion | Cast | Actor | 2nd Commercial Guy (voice) |
 Dave B. Mitchell | Cast | Actor | 1st Commercial Guy (voice) |
 Fletcher Sheridan | Cast | Actor | Cy (voice) |
| Person | Type | Job | Role(s) |
