Mervyn Pinfield (28 February 1912 - 20 May 1966) was a British television producer and director working for the BBC during the 1950s and 1960s. He was the associate producer on the BBC television series Doctor Who from the first episode of An Unearthly Child to The Romans, during Verity Lambert's tenure as producer.
Pinfield was a highly experienced producer and director. Before joining the BBC early in the 1950s to work on live drama at Alexandra Palace, he spent over four years in 'weekly rep' as Director/Theatre Manager at the Royalty Theatre, Morecambe. He was appointed to support the less experienced Lambert, as Doctor Who was her first production as a producer. In the event, she proved so adept at the job that his assistance was rarely needed, and he performed more of an advisory role.
He also directed Episodes 1 to 4 of The Sensorites, The Space Museum and Episodes 1 & 2 of Planet of Giants for the series, and worked as director on other BBC series such as Compact (Day Of Deliverance and Fare Thee Well For I Must Leave Thee), The Monsters, and The Franchise Affair.
Pinfield was also known as the inventor of an early type of Teleprompter, or Autocue, which he called the Piniprompter.