James Marsden

Tim (voice)

Alec Baldwin

Boss Baby (Ted) (voice)

Amy Sedaris

Tina (voice)

Ariana Greenblatt

Tabitha (voice)

Jeff Goldblum

Dr. Armstrong (voice)

Eva Longoria

Carol (voice)

James McGrath

Wizzie (voice)

Jimmy Kimmel

Grandpa (Ted Sr.) (voice)

Lisa Kudrow

Grandma (Janice) (voice)

Raphael Alejandro

Nathan / Lead Baby Ninja (voice)

Serenity Reign Brown

Meghan (voice)

David Soren

Jimbo (voice)

Nicholas Gist

The Triplets (voice)

James Ryan

Story Bear (Connie) (voice)

David P. Smith

Movie Patron (voice)

Nova Reed

Little Bo Peep Baby (voice)

Molly K. Gray

Creepy Girl (voice)

Ashlyn Lundahl

'No' Girl (voice)

Dave Needham

Glue Baby (voice)

Tom McGrath

Dr. Tiffany Hamilton (voice)

Reyn Doi

Box Kid (voice)

Collin Erker

Time Out Kid (voice)

Walt Dohrn

Baby Bouncer (voice)

April Lawrence

Acorn Center Computer (voice)

Miles Bakshi

Young Tim Voice-Over (voice)

Jimmy Moneta

Additional Voices (voice)

Kristin Lowe

Pageant Mom 1 (voice)

Marjorie Cohn

Pageant Mom 2 (voice)

Connor Albrecht

Dreidel Kid (voice)