Freddie Highmore
August Rush

Keri Russell
Lyla Novacek

Jonathan Rhys Meyers
Louis Connelly

Terrence Howard
Richard Jeffries

Robin Williams
Maxwell "Wizard" Wallace

William Sadler
Thomas Novacek

Marian Seldes
The Dean

Mykelti Williamson
Reverend James

Leon Thomas III
Arthur

Aaron Staton
Nick

Alex O'Loughlin
Marshall

Jamia Simone Nash
Hope

Ronald Guttman
Professor

Bonnie McKee
Lizzy

Michael Drayer
Mannix

Jamie O'Keeffe
Steve

Becki Newton
Jennifer

Tyler McGuckin
Peter

Megan Gallagher
Megan

Anais Martinez
Backbeat

Bilal Bishop
Roller Bull

Michael R. Hammonds II
Feedback

Timmy Mitchum
Joey

Henry Caplan
Bill

John Knox
Club Manager

Amy V. Dewhurst
Receptionist

Victor Verhaeghe
Cop

Darrie Lawrence
Old Neighbor

Sean Haberle
Frank

Jamal Joseph
Driver

Robert Aberdeen
Record Executive

Georgia Creighton
Apartment Owner

Joshua Jaymz Doss
Orphanage Kid

Craig Johnson
Orphanage Boy

Dominic Colón
Policeman

Zach Page
Child Guitar Player

Charles Mack
Gospel Soloist

Amma Agyapon
Gospel Singer

Adia Beckford
Gospel Singer

Dietrice A. Bolden
Gospel Singer

Dina Gardener
Gospel Singer

Luther Isler
Gospel Singer

Raymond Johnson
Gospel Singer

Joyce Walker Joseph
Gospel Singer

Willana Mack
Gospel Singer

Lamar Antwon Robinson
Gospel Singer

Talif Showers
Gospel Singer

Carlton Taylor
Gospel Singer

Yvette Bodrick
Street Sound Circle

Crystal A. Elliott
Street Sound Circle

Jindai Joseph
Street Sound Circle

Jacquelen Singleton
Street Sound Circle

Travis Veada
Street Sound Circle

Jasmine Pauline Wigfall
Street Sound Circle

John Farrer
Violinist (uncredited)