Giles trained at Mountview Theatre School. 
His theatre credits include playing Christopher Molomo in Playboy of the Western World (Abbey Theatre Dublin), Gary Coleman in Avenue Q (Noel Coward Theatre), playing Sammy Davis Junior in The Rat Pack Live from Las Vegas (The Strand Theatre), Quickly Robinson in Jailhouse Rock (The Piccadilly Theatre and Theatre Royal Plymouth), Luther in 125th Street (Shaftesbury Theatre) and Mr Jefferson in Rent (Prince of Wales Theatre). You Don’t Kiss (Stratford Circus), Up On The Roof (Chichester Festival Theatre), Ariel The Tempest (world tour with the RSC), Six Degrees of Separation (Sheffield Crucible), Generations Of The Dead (The Young Vic) Bill Shakespeare’s Italian Job (The Gilded Balloon and the Playbox Theatre Warwick), Demon Headmaster and The Animals of Farthing (The Pleasance Theatre).

National Theatre credits include, Death And The Kings Horsemen, The Hour We Knew Nothing Of Each Other, Troilus And Cressida, Candide Honk! And Darker Face Of The Earth.

Film and TV appearances include London Boulevard for director William Monahan.  Horrible Histories and Doctors for the BBC. Giles is also a very gifted composer and musician.

David as visual artist… his creations have earned: an exhibit at Caesars Palace Las Vegas’ Galleria di Sorrento; a grant fromThe Sierra Arts Foundation for UPtown DOWNtown ARTown (RoadArt); a showing in the Flamingo Hilton Reno’s showroom foyer (Jazz Series); purchased art pieces being displayed in popular Northern-Nevada restaurants; hostings of sculpture at places such as the DMV, The National Automobile Museum, and now a local college.