Walker is a reboot of the 1990s western drama series Walker, Texas Ranger, developed by Anna Fricke for The CW. In January 2020, The CW ordered the project directly to series, bypassing a traditional television pilot.

Lindsey Morgan's character Micki left the Texas Rangers and returned to San Antonio in the storyline after Morgan herself decided to leave the production during season 2 for personal reasons.

Jared Padalecki's real-life wife, Genevieve Padalecki, was cast in a recurring role as Cordell's late wife Emily Walker.

Colin Ford, who played young Sam Winchester on Supernatural alongside Jared Padalecki, appeared several times in season 3 as a soldier-aged version of Walker.

The Austin City Council approved $141,326 in incentives on October 15, 2020, to allow the series to film in Austin, while the Texas Film Commission planned to offer a $9.3 million incentive for the production.

To keep the series filming in Austin for season 2, the Austin City Council agreed to give nearly $214,000 in incentives, and for season 3 it granted $245,471.

A prequel series titled Walker: Independence was developed with Padalecki as executive producer and Fricke as showrunner, starring Katherine McNamara as Abby Walker, an ancestor of Cordell Walker; it premiered in October 2022 but was canceled after one season.

The Walker pilot was The CW's most-watched telecast since January 30, 2018, and its most-watched season premiere since The Flash's season 4 premiere in October 2017, also attracting the largest Live+7-day viewership for a new series since 2016.