Neagley is a spin-off of the television series Reacher, created by Nick Santora and Nicholas Wootton and based on the character originally created by author Lee Child.

The series received a full series order from Amazon Prime Video in October 2024, produced by Amazon MGM Studios, Skydance Television, and CBS Studios.

By August 2025, Paramount Television Studios had taken over production of the series following the merger of Skydance Television's parent company Skydance Media with CBS Studios' parent Paramount Global into Paramount Skydance.

Maria Sten reprises her role as Frances Neagley from Reacher, while Alan Ritchson makes a guest appearance reprising his role as Jack Reacher.

In February 2025, Greyston Holt, Jasper Jones, Adeline Rudolph, Matthew Del Negro, and Damon Herriman were cast as series regulars.

Maria Sten expressed excitement about exploring Neagley's personal life in depth, noting that the character has a history and severe personal issues she couldn't explore while on Reacher.

Principal photography took place in Toronto, beginning on February 18, 2025, and wrapping on June 7, 2025.