Andy Diggle was born and raised in London, England.

Diggle took over editing 2000 AD and Judge Dredd Megazine in the year 2000 and, as editor, was credited (most frequently by David Bishop, who originally employed him) as having spearheaded a return to the "old school" values of 2000 AD. While at 2000 AD he wrote a number of stories, including the Judge Dredd spin-off Lenny Zero with Jock, with whom he would continue to collaborate after his move to American comic books.

Diggle spent a total of five years under exclusive contract to DC Comics, for whom he wrote Lady Constantine, Batman Confidential, Year One (again with Jock), Planet Heist and Hellblazer.

This was followed by Guy Ritchie's Gamekeeper, which was shortly thereafter optioned by Warner Bros, for Virgin Comics.

Diggle also wrote the webcomic prequel to the Bionic Commando game, after having been hired by Capcom to script a playable test level during game development.

In 2008, Andy Diggle was announced as the new writer of Thunderbolts, his first work at Marvel Comics since his Punisher one-shot. The changes in the Thunderbolts were part of the Secret Invasion-aftermath storyline, Dark Reign, and Diggle also wrote a limited series which ties into it, Dark Reign: Hawkeye.

Diggle signed an exclusive deal with Marvel early in 2009 and would go on to take over the writing of Daredevil after Ed Brubaker's departure in issue #500, wrote Dark Reign: The List - Daredevil and the main limited series in the Daredevil storyline Shadowland.

Comics work includes:

• Lenny Zero (with Jock, collected in Mega-City Undercover , 160 pages, Rebellion, January 2008, ISBN 1905437528):
• "Lenny Zero" in Judge Dredd Megazine (vol. 3) #68, 2000)
• "Dead Zero" in Judge Dredd Megazine (vol. 4) #1-2, 2001)
• "Wipeout" in Judge Dredd Megazine vol. 4) #14-15, 2002)

• Judge Dredd vs. Aliens: Incubus (with co-author John Wagner and art by Henry Flint, in 2000 AD #1321-1335, 2003, tpb, 104 pages, Rebellion, 2003, ISBN 1-904265-10-3, Dark Horse, 2004, ISBN 1-56971-983-7)
• Snow/Tiger: "Pax Americana" (with Andy Clarke, in 2000 AD #1336-1342, 2003)
• "Payback" (with Henry Flint, in Star Wars Tales 18, 2003)
• Lady Constantine (with Goran Sudzuka, 4-issue mini-series, Vertigo, 2003, tpb, 96 pages, 2006, Titan, ISBN 1-84576-263-0 DC, ISBN 1-4012-0942-4)
• The Losers #1-32 (with Jock, DC, 2003—2006)
• Swamp Thing: Bad Seed (with Enrique Breccia, DC, 2004, tpb, collects Swamp Thing #1-6, 144 pages, 2005, Titan ISBN 1-84023-954-9 DC ISBN 1-4012-0421-X)
• Tharg's Future Shocks: "Red Moon" (with Kev Walker, in 2000 AD #1398, 2004)
• Adam Strange: Planet Heist (with Pascal Ferry and Dave McCaig, DC, 8-issue limited series, 2004—2005, tpb, 192 pages, 2005, ISBN 1-4012-0727-8)
• Silent Dragon (with Leinil Francis Yu, Gerry Alanguilan, Wildstorm, 6-issue limited series, 2005, tpb, 144 pages, 2006, ISBN 1-4012-1104-6)
• Punisher: "Silent Night" (with Kyle Hotz, one shot, collected in Punisher: Very Special Holidays, 120 pages, Marvel, May 2006, ISBN 0-7851-2220-6)
• Batman Confidential (with Whilce Portacio and Richard Friend, DC, 6-issue limited series, December 2006 - June 2007 , collected in Batman: Rules of Engagement, 160 pages, ISBN 1401214814)
• Guy Ritchie's Gamekeeper (with Guy Ritchie and Mukesh Singh, Virgin Comics, March 2007)

• Hellblazer #230-244, 247-249 (Vertigo, March 2007 - November 2008):
• Joyride (with Leonardo Manco, 192 pages, Vertigo, February, 2008, ISBN 1-40121-651-X, Titan, April 2008, ISBN 1845767756) collects:
• "In at the Deep End" (Hellblazer #230-231, 2007)
• "Wheels of Chance, Systems of Control" (Hellblazer #232-233, 2007)
• "Joyride" (Hellblazer #234-237, 2007)
• The Laughing Magician (128 pages, August 2008, ISBN 1-40121-853-9) collects:
• "The Smoke" (with Danijel Zezelj, Hellblazer #238, 2007)
• "The Passage" (with Leonardo Manco, Hellblazer #239, 2007)
• "The Laughing Magician" (with Leonardo Manco, Hellblazer #240-242, 2008)
• Roots of Coincidence (128 pages, May 2009, ISBN 1-40122-251-X) collects:
• "The Mortification of the Flesh" (with Giuseppe Camuncoli, Hellblazer #243-244, 2008)
• "The Roots of Coincidence" (with Leonardo Manco, Hellblazer #247-249, 2008)

• Year One (with Jock, 6-issue limited series, DC, July—September 2007, tpb, hardcover, 160 pages, Titan Books, May 2008, ISBN 1845767276, DC, April 2008, ISBN 1401216870)
• Bionic Commando: Chain of Command (with Colin Wilson, game tie-in, ongoing)

• Thunderbolts #126-136 (with Roberto De La Torre, Marvel Comics, January—November 2009) collected as:
• Burning Down The House (collects Thunderbolts #126-129, 112 pages, hardcover, August 2009, ISBN 0-7851-3152-3)
• Dark Reign: Deadpool/Thunderbolts (includes Thunderbolts #130-131, 96 pages, softcover, July 2009, ISBN 0-7851-4090-5)
• Widowmaker (collects Thunderbolts #133-136, premiere hardcover, 120 pages, December 2009, ISBN 0-7851-4006-9)

• Dark Reign: Hawkeye (with art by Tom Raney, 5-issue limited series, Marvel Comics, June 2009 - March 2010)
• Daredevil #501-ongoing (with Roberto De La Torre and Matt Hollingsworth, Marvel Comics, October 2009-ongoing)
• Dark Reign: The List - Daredevil (with art by Billy Tan, one-shot, Marvel Comics, November 2009)
• Shadowland (with Billy Tan, Marvel Comics, 5-issue limited series, August 2010, forthcoming)