Jonathan Newth is a British actor who has appeared extensively in British television drama for over 50 years.
Newth trained at the Central School of Speech and Drama.
Newth's theatre work includes appearances with the RSC, in the West End and on Broadway.
Newth's television credits include Emergency Ward 10, The Six Wives of Henry VIII, Ace of Wands, The Troubleshooters, Z-Cars, Callan, Van der Valk, The Brothers, Softly, Softly, Poldark, Doctor Who (Underworld), Notorious Woman, Secret Army (Barsacq), The Professionals, The Nightmare Man, The Day of the Triffids, Tenko (Colonel Clifford Jefferson), Triangle, Angels, Juliet Bravo, After Henry, The Adventures of Sherlock Holmes ("The Bruce-Partington Plans"), Boon, Bugs, The Bill, Agatha Christie's Poirot (Dumb Witness), Peak Practice and Heartbeat.

North Sea Hijack
1980 · as Kirk

The Affair of the Necklace
2001 · as Magistrate de Marce

Incognito
1997 · as Judge

The Fools on the Hill
1986 · as Mr Piggot-Smythe

Carry On Spying
1964 · as Guard (uncredited)

Pope John Paul II
1984 · as Archbishop Adam Sapieha

Spider's Web
1982 · as Henry Hailsham-Brown

Champions
1984 · as Mr Griffin Jones

Accounts
1983 · as James

Certainties and Doubts
1979

Tennis Court
1984 · as Harry Dowd

Yellow Dog
1973 · as Tim

The Nightmare Man
1981 · as Colonel Howard

A Voyage Round My Father
1984 · as Boustead

Doctor Who: Underworld
1978 · as Orfe

The Suicide Club
1970 · as Lt. Brackenbury Rich

Remembering Douglas Camfield
2013

The Case of Marcel Duchamp
1984 · as Darriand