Gimple, who joined the show in Season 2, will replace Season 3 head writer-producer Glen Mazzara as showrunner for Season 4.
Mazzara cited creative differences with the cable network when he confirmed his departure from the show late last month.
Mazzara replaced showrunner Frank Darabont, who was fired just before the series' Season 2 premiere.
Starring Andrew Lincoln and Norman Reedus, the show is now in the middle of its third season.
2014: The Year in Music [PHOTOS]