Gimple grew up in Berkeley Heights, New Jersey, and graduated from Governor Livingston High School. He graduated from the University of Southern California's School of Cinema-Television.
Gimple was a writer on NBC's Life and Fox TV's Drive, and ABC's FlashForward. He co-wrote the script of Ghost Rider: Spirit of Vengeance alongside Seth Hoffman and David S. Goyer.
He has also worked on Disney's Pepper Ann and as a writer for Simpsons Comics. Gimple created the cartoon Fillmore! and the comic book Heroes Anonymous with Bill Morrison.
In 2011 he joined the crew of AMC's The Walking Dead as a producer and writer for the second season. He wrote the episodes "Save the Last One", "Pretty Much Dead Already", and "18 Miles Out" (with Glen Mazzara), and "Hounded", "Clear", and "This Sorrowful Life" for the third season. In January 2013, following the departure of Glen Mazzara as showrunner, it was announced that Gimple would succeed him. Despite being showrunner, Gimple continues to write episodes; for season four, he wrote "30 Days Without An Accident", "The Grove", and "A" (with Angela Kang) and for season five the season premiere "No Sanctuary", the midseason premiere "What Happened and What's Going On", and the season finale "Conquer".
With his work on The Walking Dead, he is known best for a love of the comics and keeping the show remaining faithful to the comics, which has proven to be especially well-received by comic book readers.
- The Hollywood Reporter Interview by Lesley Goldberg (July 11, 2013)