David Brierly (also known as David Brierley, born 1935, Yorkshire and died on 10 June 2008) was the second actor to provide the voice for K9 when he had Robotitus, beginning with The Creature from the Pit and ending with the uncompleted Shada. He also provided the voice for Erato in The Creature from the Pit.
He succeeded John Leeson, K9's original voice (Leeson returned to the role the following season).
Brierly appeared in other television programmes, including Z-Cars, Juliet Bravo, and The Tripods. K9 was his most notable role. Most recently he appeared as himself in the 2000 documentary K9 Unleashed.
Among Brierly's hobbies were sailing and long-distance running.