Born in Thornaby-on-Tees in 1947, Griffiths began his career treading the boards with the Royal Shakespeare Company before making his feature film debut in 1975's It Shouldn't Happen to a Vet. Minor roles in the likes of Superman II, The French Lieutenant's Woman, Chariots of Fire and Ghandi soon followed and he also made the transition to television, appearing in the lead in the BBC's 1982 techno-thriller TV series Bird of Prey.
After a breakout role as Uncle Monty in the 1987 comedy classic Withnail & I, Griffiths went on to feature in a number of movies throughout the 90s such as King Ralph, The Naked Gun 2½: The Smell of Fear and Sleepy Hollow, whilst headlining another BBC series as Detective Inspector Henry Crabbe in Pie in the Sky between 1994 and 1997. However, it is role as Vernon Dursley for which he will best be remembered, having portrayed the character in Harry Potter and the Philosopher's Stone and the sequels Harry Potter and the Chamber of Secrets, Harry Potter and the Prisoner of Azkaban, Harry Potter and the Order of the Phoenix and Harry Potter and the Deathly Hallows: Part 1.