Kyle Mooney as James Pope

Mark Hamill as Ted Mitchum

Jorge Lendeborg Jr. as Spencer

Matt Walsh as Greg Pope

Michaela Watkins as Louise Pope

Ryan Simpkins as Aubrey Pope

Greg Kinnear as Detective Vogel

Alexa Demie as Meredith

Beck Bennett as Detective Bander

Claire Danes as Emily

Chance Crimin as Logan

Jane Adams as April Mitchum

Andy Samberg as Eric

Kate Lyn Sheil as Arielle Smiles

James Anthony Green as Police Officer

Kim Fischer as Female Reporter

Kelly Chapman as News Anchor

Nick Rutherford as Brigsby Bear fan

Reagan Pineda as Reality Talking Head

Kiera Milan Hendricks as Young Smiles Sisters

Tim Heidecker as Coach Brad

Rex Morgan as Gordo

Ellery Davidson as Hannah Slice

Christopher Sullivan as FBI Agent

Joseph Paul Branca as Space Alien

Nikolas Mikkelsen as Theatre Patron

Matthew P. Watts as Prison Guard

Ashlyn Brooke Anderson as Wizzle Prince (uncredited)

Yvonne D Bennett as Party Guest (uncredited)

Kami Christiansen as Nurse (uncredited)

Paul Nathan Cuthbert as Prison Visitor (uncredited)

Teresa Duran-Norvick as Premiere Audience (uncredited)

Gerry Garcia as (uncredited)

Angella Joy as Reporter (uncredited)

Marilyn Miller as Court Reporter (uncredited)

Chris Provost as Prison Guard (uncredited)

Seth Williams as Cameraman (uncredited)

Julio Torres as Man Getting Haircut (uncredited)