Born and educated in England, Thwaites began his career as a child actor appearing in a number of television series over a ten year period.  At the age of eighteen, whilst an undergraduate at London University, he co-founded a film production company set up a small production company which developed a number of projects and produced 'The Skip', a short film aired by Channel Four.

Thwaites moved to Los Angeles in 2000 and after a two-week stint as an intern at Village Roadshow, joined Mike Medavoy as his assistant at Phoenix Pictures.   Climbing the executive ladder at Phoenix Pictures, Thwaites is now Co- President of Production, where he helps oversee the development of the company's slate. 

Thwaites is an executive producer on "All the King's Men", starring Sean Penn, Jude Law, Kate Winslet, James Gandolfini, Mark Ruffalo, Patricia Clarkson and Anthony Hopkins; a producer on "Miss Potter", starring Reneee Zellweger, Ewan McGregor and Emily Watson; and an executive producer on "License to Wed", starring Robin Williams, Mandy Moore and John Krasinski.