The series is based on the Kakao Webtoon webtoon Amazing Rumor by Jang Yi, and follows So Mun, a disabled high school student recruited into a group of paranormal hunters called the Counters.

Scriptwriter Yeo Ji-na left the series after writing the first 12 episodes due to differing opinions on the final storyline; episode 13 was written by director Yoo Seon-dong, and the last three episodes were written by Kim Sae-bom.

Jo Byeong-kyu, Yoo Jun-sang, Kim Se-jeong and Yeom Hye-ran were confirmed as the main cast in July 2020, with the first script reading taking place in October 2020.

The Uncanny Counter became the highest-rated series in OCN's history.

The first episode averaged 2.7% nationwide viewership (3.2% in the metropolitan area, peaking at 4.1%), while the finale, episode 16, reached the series' highest rating of 11% nationwide.

A special broadcast titled 'The Uncanny Return' aired on February 7, 2021, reuniting much of the main cast shortly after the first season concluded, ahead of the confirmed second season.

Two episodes (9 and 10) were pulled from their original December 2020 broadcast dates due to internal network circumstances and a special film was aired instead, with the episodes rescheduled for January 2021.

Actress Yeom Hye-ran won the Best Supporting Actress (TV) award at the 57th Baeksang Arts Awards in 2021 for her role as Chu Mae-ok, and the series also won the Grand Prize for Drama (PP Works Award) at the 2021 Cable TV Broadcasting Awards.