Gimple - who has previously written five episodes of the zombie drama - replaces Glen Mazzara, who was dropped from the series in December.
Mazzara himself had previously replaced original showrunner Frank Darabont in the early stages of The Walking Dead's second season.
Gimple will assume the role at the beginning of the fourth season, TVLine reports, with Mazzara's final season three episodes airing from February.
In addition to working on The Walking Dead as a writer and supervising producer, Gimple has also penned episodes of FlashForward and Life and contributed to the screenplay for 2011 film Ghost Rider: Spirit of Vengeance.
[Left: Glen Mazzara / Right: Robert Kirkman]
It was recently reported that Glen Mazzara had been fired from his showrunner role for producing "a lack of material" and clashing with comic creator Robert Kirkman.
Sons of Anarchy creator Kurt Sutter - who worked with Mazzara on FX drama The Shield - later defended his former colleague, insisting that The Walking Dead is now "infinitely better because of his talent".
The Walking Dead returns to AMC on Sunday, February 10 and to FOX in the UK on Friday, February 15.
> The Walking Dead was turned down by NBC: "It was an early draft"
> The Walking Dead exec: 'The Governor is on the warpath'
Watch a promo for the return of The Walking Dead below: