Here are some of them:
Actor: Role:
Dev Patel ... Jamal K. Malik
Anil Kapoor ... Prem Kumar
Saurabh Shukla ... Sergeant Srinivas
Rajendranath Zutshi ... Director (as Raj Zutshi)
Jeneva Talwar ... Vision Mixer
Freida Pinto ... Latika
Irrfan Khan ... Police Inspector
Azharuddin Mohammed Ismail ... Youngest Salim
Ayush Mahesh Khedekar ... Youngest Jamal
Sunil Kumar Agrawal ... Mr Chi (as Sunil Aggarwal)
Jira Banjara ... Airport Security Guard #1
Sheikh Wali ... Airport Security Guard #2
Mahesh Manjrekar ... Javed
Sanchita Choudhary ... Jamal's Mother
Himanshu Tyagi ... Mr Nanda
The cast of Make Me a Millionaire - 2009 includes: Liz Hernandez
The cast of Who Wants to Be a Super Millionaire - 2004 includes: Regis Philbin as Himself - Host
The cast of An Old Appointment - 1912 includes: Marc McDermott as The Old Millionaire
The cast of The Millionaire - 2012 includes: Cindy Carpenter Andrew Cooney Elliot Gibson Miles Gibson Hugo Gibson Robert Gibson as Dad
The cast of Vegas Whales - 2003 includes: Christopher Hyslop as Dot com millionaire John Papapavlos as Millionaire Whale Joseph Venouziou as Bodyguard
The cast of Slumdog Nillionaire - 2013 includes: Coolie Mac as himself
The cast of Make Me a Millionaire - 2009 includes: Liz Hernandez
The cast of Millionaire Droopy - 1956 includes: Bill Thompson as Droopy
The cast of The Editor and the Millionaire - 1912 includes: Gladys Sylvani as Gladys Groves
The cast of The E-Millionaire Show - 2000 includes: Jon Snow as himself
The cast of One Minute Millionaire - 2011 includes: Courteney Cox as Michelle
The cast of Slumdawg Millionaire - 2009 includes: Susan Ateh Annemarie Gaillard Thomas Tevana
The cast of The Millionaire Paupers - 1919 includes: Neely Edwards as Ferdie Edward Flanagan as Percy
The cast of Who Wants to Be a Super Millionaire - 2004 includes: Regis Philbin as Himself - Host
The cast of The Millionaire and the Goose - 1913 includes: Dick Coburn as Rocks - the Millionaire Harry DeRoy as The Chef Vincente Howard as The Prospector
Rubina Ali (young Latika) is nine, so I'm guessing they are all around eight or nine.
The cast of The Changeling - 1913 includes: Harry Benham as The Millionaire Father