This work was conceived from Cygames' Nobuhiro Takenaka finding the zombie girl character "Rita" who appears in "Shink击no Bahamut Genesis" cute. The initial provisional title was "Idol Zombie".

While internal approval was taking time, an anime planning request from Saga Prefecture, the birthplace of Cygames president Kōichi Watanabe, came in, leading to the decision to set the story in Saga Prefecture. Through repeated location scouting, the work gradually moved away from typical idol anime, and the title was changed to "Zombieland Saga".

Initially, the series composition team reached out to multiple scriptwriters, but as they all submitted heavy scripts out of respect for George A. Romero, Shigeru Murakoshi, who could also write comedy, was chosen.

Kotono Mitsuishi as Tae Yamada and Yasuhiro Takado as the zombie dog Romero were both cast by director request of Muneisa Sakai, who judged that expressive veteran voice actors were necessary precisely because their characters do not speak words.

That Kotono Mitsuishi played Tae Yamada was kept secret at the start of broadcast and first revealed in the end credits of episode 3.

Kaede Hondo, who plays Sakura, is from Nagoya and had no experience using dialect. She initially felt anxious about the Karatsu dialect lines, but worked with dialect coach Mariya Fujino, a stage actress from Karatsu City, Saga Prefecture, to develop her character.

The scene in episode 2 where Police Officer A raps was not in the script. It was an ad-lib proposed on set by voice actor Hiroyuki Yoshino, who suggested "I'll do it too" in the flow of a rap battle scene, and it was adopted as-is.

During promotion, secrecy was strictly maintained, and aside from the catchphrase "New sensation zombie anime", all information was kept confidential until broadcast. At a general advance screening in Tokyo, audiences were even required to sign a confidentiality agreement.

After the final episode aired, tweets containing "Zombieland Saga" exceeded 170,000 on Twitter and ranked first in trends. On Niconico Douga's "Anime Tournament 2018", it ranked first in both the yearly and autumn polls, with Saga Prefecture accounting for 53.83% of the votes.