Bishop was sub-editor of the Judge Dredd Megazine and of Crisis, before becoming the editor of the Megazine from 1991 to 2002. He became the editor of 2000 AD just before Christmas 1995, staying four and a half years before resigning to become a freelance writer in the summer of 2000.
Bishop was responsible for discovering many new British talents, including:
Chris Halls (comics pseudonym of video director Chris Cunningham)
Jim Murray He also, with collaborator Roger Langridge, contributed the insane asylum-set strip The Straitjacket Fits.
Since leaving 2000 AD in the year 2000, Bishop has enjoyed a successful career as a freelance writer, working on novels of Doctor Who, Judge Dredd, Heroes and Nikolai Dante, as well as comic strip adventures of The Phantom. His Doctor Who novel Who Killed Kennedy, a journalist's point-of-view on the early Third Doctor stories, is highly popular with fans.Despite his successes as a comics editor and as a writer of prose, Bishop scripted many extremely unpopular comic strips in 2000 AD and the Megazine, including the comics adaptation of A Life Less Ordinary, with art by Steve Yeowell. The Spacegirls, a badly executed parody of the Spice Girls, is on the list of 2000 AD's 20 Worst Strips as chosen by fan rating on the official website. His most recent effort — a Fiends of the Eastern Front series for the Megazine — has proven much more popular with readers.Away from British comics, his work on The Phantom has won awards for the "Best Phantom story of the year" for Egmont on several occasions. Bishop introduced several new important characters to the Phantom mythos, such as the pirate queen Kate Sommerset, which grew so popular with readers that Bishop was able to make her the main character of five stories.
In 2006, Bishop also signed on to participate in the writing of stories for American publisher Moonstone Books' two collections of Phantom short stories, called Phantom Prose Anthologies.
Bishop's history of 2000 AD, in a series of articles under the banner name of Thrill Power Overload, is the most comprehensive currently available. A revised, expanded and updated book version was published in the summer of 2007 to coincide with the 30th anniversary of 2000 AD. After that sold out, a paperback edition was issued in February 2009. An expanded edition with new material by Karl Stock was released in 2017.In 2008, he appeared on 23 May edition of the BBC One quiz show The Weakest Link, beating eight other contestants to win more than £1500 in prize money.
In 2010, Bishop received his first TV drama credit on the BBC medical drama series Doctors, writing an episode called A Pill For Every Ill, broadcast on 10 February.