Kirkman was first hired by Marvel Comics to pen a revival of the 1990s Sleepwalker series, but it was canceled before being published; the contents of its first issue were included in Epic Anthology No. 1 (2004). He soon became a mainstay at Marvel, writing the "Avengers Disassembled" issues of Captain America vol. 4, 2004's Marvel Knights 2099 one-shots event, Jubilee #1–6 and Fantastic Four: Foes #1–6, a two-year run on Ultimate X-Men and the entire Marvel Team-Up vol. 3 and the Irredeemable Ant-Man miniseries.
Robert Kirkman's first comic book work was the 2000 superhero parody Battle Pope, which he co-created with Artist Tony Moore, self-published under the Funk-O-Tron label, and was adapted into a season of 8 animated webisodes that appeared on Spike TV's website in 2008. Later, while pitching a new series, Science Dog, Kirkman and Artist Cory Walker were hired to do a SuperPatriot miniseries for Image Comics. While working on that book, Kirkman and E. J. Su created the 2002 Image series Tech Jacket, which ran six issues, and the one-shot title, Cloudfall.
Shortly after the launch of Invincible, Kirkman began The Walking Dead (2003). Kirkman said in 2012 that Image had balked at publishing a comics series featuring what it felt was simply another zombie story, prompting him to say the zombies were part of an alien plot—a notion he had no intention of using except as a means of selling the project. Artist Charlie Adlard replaced Tony Moore with issue #7. Moore continued to draw covers until issue 24 as well as the first four volumes of the trade paperbacks for the series.
Kirkman and his wife live in Kentucky. Their son Peter Parker Kirkman was born April 25, 2006.
Kirkman announced in 2007 that he and Artist Rob Liefeld would team on a revival of Killraven for Marvel Comics. Kirkman that year also said he and Todd McFarlane would collaborate on Haunt for Image Comics.
In late July 2008, Kirkman was made a partner at Image Comics, thereby ending his freelance association with Marvel. Nonetheless, later in 2009, he and Walker produced the five-issue miniseries The Destroyer vol. 4 for Marvel's MAX imprint.
In 2009, Kirkman and Marc Silvestri took over the 2009–2010 Pilot Season for Top Cow Comics. The 2009/2010 Pilot Season contains a series of five one-shot pilot comics that readers will be able to vote on which becomes an ongoing series. Each series is co-created by Silvestri who also provides cover art.
In July 2010, Kirkman announced he would launch and run a new Image Comics imprint called Skybound Entertainment.
In 2011, The Walking Dead TV series was nominated for A Writers Guide of America Award for Best New Series.
Kirkman made an appearance in a 2012 episode of Adult Swim's Robot Chicken as himself where he tries to tell The Nerd and Daniel a hint, but gets eaten by the zombies.
In 2013 he was nominated for the OTFA Television Award for Best Writing in a Drama Series.
Kirkman was a Producer of the science fiction thriller Air, which starred The Walking Dead's Norman Reedus, and Djimon Hounsou. The movie was released in 2015. It was the first feature film to be produced by Skybound Entertainment.
As of November 7, 2016, Kirkman's production company Skybound Entertainment was set to produce a remake of the film An American Werewolf in London. The remake will be written and directed by Max Landis, son of the original Director John Landis. Kirkman and David Alpert would be executive producers on the film.
