- Jim Carrey
- Lloyd
- Jeff Daniels
- Harry
- Rob Riggle
- Travis / Captain Lippincott
- Laurie Holden
- Adele
- Rachel Melvin
- Penny
- Steve Tom
- Dr. Pinchelow
- Don Lake
- Dr. Meldmann
- Patricia French
- Ms. Sourpuss
- Elizabeth Cooper
- Mrs. Julie James
- Kathleen Turner
- Fraida
- Bill Murray
- Ice Pick
- Tembi Locke
- Dr. Walcott
- Paul Blackthorne
- Emergency Room Doctor
- Brady Bluhm
- Billy
- Eddie Shin
- Gordy
- Tommy Snider
- Tom
- Atkins Estimond
- Gus
- Lindsay Ayliffe
- Professor Garabedian
- Matty Cardarople
- Inventor #1
- Michael Yama
- Harry's Dad
- Nancy Yee
- Harry's Mom
- Jeff Sumner
- Convention Official
- Grant James
- Mr. Stainer
- Taylor St. Clair
- Mrs. Stainer
- Erin Allin O'Reilly
- Asylum Nurse #1
- Nancy Byers Farrelly
- Asylum Nurse #2
- Derek Holland
- Asylum Patient
- Brendan Boyle
- Asylum Patient
- Swizz Beatz
- Ninja Leader
- Mike Cerrone
- Trucker
- Sean Gildea
- Trucker's Pal
- Maia Moss-Fife
- Receptionist
- Bryan Dilbeck
- Dr. Dilbeck
- Kassidy Claire
- Fanny Age 5
- Brett Wyman
- Inventor #2
- Jo Helton
- Mrs. Snergle
- Erika Bierman
- Fanny Age 13
- Edward Barbanell
- Nursing Home Orderly
- Mariann Neary
- Farmer's Wife
- John Imlay
- Farmer
- Jon Barinholtz
- Inventor No. 3
- Dalton E. Gray
- Young Harry
- Lucas Daniels
- Bartender
- June Shannon
- Harry's Trailer Park Wife
- Carly Craig
- Young Fraida
- Carter Hicks
- Bus Kid
- Baxter Cooper Rogers
- Prom Date
- Sandra Dorsey
- Stuffy Woman
- Arielle Liberman
- Emergency Room Nurse
- Jon Barry
- Emergency Room Orderly
- Jesse Gines
- Emergency Room Orderly
- Robin O'Neal Sorensen
- Emergency Medical Technician #1
- Chris Randall Sorensen
- Emergency Medical Technician #2
- Daniel Greene
- Wheelchair Ninja
- Will Coogan
- Room Service Waiter
- Caryle Seim
- Trailer Grandma
- Danny Murphy
- Joystick Victim
- Rhomeyn Johnson
- Bus Driver
- Walt Arnett
- KEN Conference Attendee
- Kevin Barnett
- KEN Conference Attendee
- Brad Blank
- KEN Conference Attendee
- Ricky Blitt
- KEN Conference Attendee
- Rich Brown
- KEN Conference Attendee
- Troy Brown
- KEN Conference Attendee
- Rob Cohen
- KEN Conference Attendee
- James Freeman
- KEN Conference Attendee
- Jeremy Garelick
- KEN Conference Attendee
- Julius Sharpe
- KEN Conference Attendee
- Boyd Hale
- KEN Conference Attendee
- Derek Iversen
- KEN Conference Attendee
- Brian Jarvis
- KEN Conference Attendee
- Pete Jones
- KEN Conference Attendee
- Trevor Kennish
- KEN Conference Attendee
- T.J. King
- KEN Conference Attendee
- Blake McCormick
- KEN Conference Attendee
- Michael McCrudden
- KEN Conference Attendee
- Patrick Meighan
- KEN Conference Attendee
- Brendan O'Brien
- KEN Conference Attendee
- Chris Pappas
- KEN Conference Attendee
- Leo Resig
- KEN Conference Attendee
- Tiffany Resig
- KEN Conference Attendee
- Rocky Russo
- KEN Conference Attendee
- Deepak Sethi
- KEN Conference Attendee
- Chris Sheridan
- KEN Conference Attendee
- Danny Smith
- KEN Conference Attendee
- Jeremy Sosenko
- KEN Conference Attendee
- Samantha Thomas
- KEN Conference Attendee
- Trent Thomas
- KEN Conference Attendee
- Trashel Thompson
- KEN Conference Attendee
- John Viener
- KEN Conference Attendee
- Dave Walpole
- KEN Conference Attendee
- Wellesley Wild
- KEN Conference Attendee
- Al Wisne
- KEN Conference Attendee
- Smith Anthony
- Neighborhood patron
- Sade Ariel
- Prom Attendee
- David G. Baker
- Hospital Visitor
- Paul Bednarz
- KEN Convention Employee
- Knox Bentley
- Ken Conference Attendee
- Jesse Clark
- Club-Goer
- Quan Clark
- KEN Conference Attendee
- Jennifer Cocker
- Young Inventor
- Daniel Collins
- Ken Conference Attendee
- R.J. Conners
- Hospital Patient
- Bennett Wayne Dean Sr.
- Hospital Visitor
- Derrick Dean
- Hospital Visitor
- Doris Dean
- Hospital Visitor
- John Deifer
- Mental Patient
- Alice Dinnean
- Janessa - Prom Attendee
- Jacklyn Edney
- Ken Con Scientist
- David Emmett
- Hospital Visitor
- Gregory Fears
- Man at Gas Station
- Shelton Foreman
- Patron
- Abigail Gamache
- Prom Attendee
- Eric Gletzlaf
- Ice Cream Kid
- Jeff Glover
- Orderly
- William Goodrum
- Prom Singer
- Cody Mark Hanna
- Audience Member
- Walter Hendrix III
- Street Patron
- Llauryn Hendrix
- Conference Patron
- Lauren Henneberg
- KEN Conference Attendee
- Michelle Brown Houston
- Science Patron
- Ron Hudson
- Club Patron
- Kathlene Huslin
- Ken Vendor
- Billy Boy Johnson
- Scientist
- Darien Johnson
- KEN Convention Attendee
- Jeffrey Karantza
- Doctor
- Angela Kerecz
- Waitress
- Debi Kimsey
- Knitting Lady on porch
- Rob Koebel
- Officer Stone - El Paso Police
- Lex Lang
- Mr. Felcher the Mortician
- Stephanie Long
- Hospital Patient
- Megan Lovell
- KEN Conference Attendee
- Anthony R. McClara
- Security Guard
- Andrew S. McMillan
- Mental Patient
- Richard Melton
- Chaperone
- John Merical
- Neighbor
- Cam Neely
- Sea Bass
- Ryan Nesset
- Pedestrian
- David Pascua
- Mariachi Trumpet Player
- William R Phillips
- Waiter
- Barbra Prince
- Street Patron
- Allison Rene
- Trophy Wife / Mrs. Rhode Island (uncredited)
- Orbert Rogers
- Park Patron
- Niki Romano
- KEN Conference Attendee
- Anthony Rosso
- Nerd
- Chris Smith
- Homeless Guy
- Dereck Seven Smith
- Convention Center Nerd
- Dea Spicer
- Bookstore Patron
- Athena Stuebe
- Restaurant Patron
- Sienna Stuebe
- Restaurant Patron
- Lauren Emily Townsend
- Conference Patron
- Josh Turner
- KEN Convention Employee
- Wenzell Washington
- Convention Attendee
- Christina Michelle Williams
- KEN Convention Employee
- Ashton Lee Woolen
- Extra
- Jessica Yoshimura
- Allison Frugal-philanthropist
- Dawn Young-McDaniel
- Nurse
