Lloyd started working in comics in the late 1970s, drawing for Halls of Horror, TV Comic and a number of Marvel UK titles. With writer Steve Parkhouse, he created the pulp adventure character Night Raven.

Dez Skinn set up Warrior magazine in 1982, he asked Lloyd to create a new pulp character. Lloyd and writer Alan Moore created V for Vendetta, a dystopian adventure featuring a flamboyant anarchist terrorist fighting against a future fascist government. Lloyd, who illustrated in cinematic chiaroscuro, devised V's Guy Fawkes-inspired appearance and suggested that Moore avoid captions, sound effects and thought balloons. After Warrior folded in 1984, the series was reprinted and continued in colour by DC Comics and collected as a graphic novel in 1995. It was adapted into a film released in 2006.

Lloyd has also worked on Espers, with writer James D. Hudnall, for Eclipse Comics; Hellblazer, with writers Grant Morrison and Jamie Delano,and War Story, with Garth Ennis, for DC; and Global Frequency, with Warren Ellis, for Wildstorm. With Delano he also drew The Territory for Dark Horse, where he has also worked on some of their licensed properties like Aliens and James Bond. He has also created a graphic novel, Kickback, for French publisher Editions Carabas.