Danny DeVitoThe Lorax (voice) Zac EfronTed Wiggins (voice) Rob RiggleMr. Aloysius O'Hare (voice) Taylor SwiftAudrey (voice) Jenny SlateMrs. Wiggins (voice) Betty WhiteGrammy Norma (voice) Nasim PedradOnce-ler's Mom (voice) Joel Swetow1st Marketing Guy (voice) Michael Beattie2nd Marketing Guy (voice) Elmarie WendelAunt Grizelda (voice) Dave B. Mitchell1st Commercial Guy (voice) Dempsey Pappion2nd Commercial Guy (voice) Danny CookseyBrett / Chet (voice) Stephen TobolowskyUncle Ubb (voice) Chris RenaudForest Animals (voice) / Director Sherry LynnAdditional Voices (voice) Mickie McGowanAdditional Voices (voice) Jack AngelAdditional Voices (voice) Bob BergenAdditional Voices (voice) Dee Dee GreeneAdditional Voices (voice) Danny MannAdditional Voices (voice) Fletcher SheridanCy (voice) John CyganAdditional Voices (voice) Bill FarmerAdditional Voices (voice) Jess HarnellAdditional Voices (voice) Mona MarshallAdditional Voices (voice) Laraine NewmanAdditional Voices (voice) Jan RabsonAdditional Voices (voice) Claira Nicole TitmanAdditional Voices (voice) Jim WardAdditional Voices (voice) Chris RenaudForest Animals (voice) / Director Cinco PaulScreenplay / Executive Producer / Songs Ken DaurioScreenplay / Executive Producer Audrey GeiselExecutive Producer Robert TaylorAssociate Producer Yarrow CheneyProduction Design John PowellOriginal Music Composer Massimo RubertoMusic Supervisor Randy ThomSound Re-Recording Mixer Gary RizzoSound Re-Recording Mixer Dennis LeonardSupervising Sound Editor Daniel LaurieAdr Supervisor Carter GoodrichCharacter Designer Eric GuillonCharacter Designer Mike ReissStory Consultant Dave RosenbaumStory Supervisor 
