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)