Mark Elstob

 was an actor who appeared in several Big Finish Productions. He started his career mainly in the theatre with occasional appearances in film and television, one of these being a stint in the soap opera Emmerdale.

More recently, Elstob has become the new voice of Number Six in Big Finish's audio revival of.

Doctor Who Main Range

 * Harry Houdini's War - Oberst Brandt / Reynolds

The Fourth Doctor Adventures

 * The Dreams of Avarice - Drones / Aide / Sergeant

Charlotte Pollard: The Further Adventuress

 * The Mummy Speaks! - Le Roi / Baron / Carriage Driver / Barker
 * The Slaying of the Writhing Mass - Kelyan

The War Doctor

 * Pretty Lies - Editor / Old Man

The Tenth Doctor Adventures

 * The Sword of the Chevalier - Joxer / Butler

The Third Doctor Adventures

 * Operation: Hellfire - Wing Commander Douglas Quilter
 * The Annihilators - Grestrenor Leader / DC Staniton / Dr Daniels / Sergeant Major Roach

Bernice Summerfield

 * Every Dark Thought - Chorus

Gallifrey

 * Hostiles - Qatal

The War Master

 * Beneath the Viscoid - Glortz

The Churchill Years

 * I Was Churchill's Double - Kaiser Wilhelm III / John Logie Baird

Torchwood

 * The Dying Room - Hans Grau