Tomlinson began his career at IPC Magazines in 1961, initially as a writer and then later as sub-editor on the comics Lion (1961–1967) and then Tiger, becoming editor of the latter title in 1969.
He later became the founding editor of the comics Roy of the Rovers (1976), Speed (1980), Scream!
He became Group Editor for Sports and Adventure in 1976, and oversaw the launch of the new Eagle in 1982, something for which he had long campaigned.
Tomlinson wrote most of the stories in Wildcat, as well as "Death Wish" for Speed, all of which continued to appear in Eagle after the cancellation of the comics in which they had originated.
Tomlinson has written two books of memoirs about his career in the British comics industry: