Lloyd was born in 1925 in Wales. As a producer, he reached the front rank of BBC television drama. He began his television career working on popular series in the 1960s. He was the third producer on Doctor Who. His tenure ran for two seasons, from The Celestial Toymaker through The Enemy of the World (excepting The Tomb of the Cybermen). His most important contribution to the programme was developing the notion of regeneration to replace the lead actor. This arose following continuing health difficulties for William Hartnell.