The series is a true crime anthology based on the podcast of the same name by Christopher Goffard, and was initially ordered for two seasons by Bravo.

Although season one and two aired on the same series, the show moved from Bravo to USA Network ahead of the second season's premiere in 2020.

The anthology format was confirmed when the second season was announced as Dirty John: The Betty Broderick Story, telling an entirely different true crime story from season one.

Connie Britton was announced in the lead role of Debra Newell in March 2018, followed shortly after by Eric Bana joining as the title character John Meehan in April 2018.

Amanda Peet and Christian Slater were cast as Betty and Dan Broderick for the second season, with Rachel Keller later joining the main cast.

A companion documentary titled Dirty John: The Dirty Truth was ordered to air alongside the main series, investigating the real John Meehan through the accounts of those he deceived; it premiered on Oxygen on January 14, 2019.

The show's official premiere event at NeueHouse Hollywood in Los Angeles had its red carpet arrivals canceled out of respect for the victims of the Woolsey Fire, which was still burning in the region at the time.

Connie Britton received nominations for the Golden Globe Award for Best Actress and the Critics' Choice Television Award for the first season, while the second season was significantly better received by critics, holding a 90% approval rating on Rotten Tomatoes compared to 71% for season one.