The series premiere aired as the lead-out program for Super Bowl LI and was watched by 17.6 million people, making it the most viewed episode in the entire 24 franchise's history, though it was the lowest post-Super Bowl program viewership since Alias in 2003.

Showrunner Howard Gordon explained that the concept originated from an idea unrelated to 24, which was reworked into a story based on a real special ops team that killed Osama bin Laden and struggled to adjust to civilian life after their identities were hidden.

Producers described the series as 'an expansion of the 24 universe' rather than a reboot, and chose to build the show around a new protagonist instead of Jack Bauer because they felt his story had been fully told in 24: Live Another Day.

Corey Hawkins was the only actor considered for the lead role of Eric Carter after casting director Lisa Miller Katz saw his performance in Straight Outta Compton.

Miranda Otto immediately accepted the role of Rebecca Ingram because she wanted to play a character involved in 'that world of CIA and terrorism,' similar to her role on Homeland.

Producers hinted that Mary Lynn Rajskub might reprise her role as Chloe O'Brian, despite earlier statements that no former 24 characters would appear; ultimately Carlos Bernard returned as Tony Almeida in a recurring role.

Kiefer Sutherland repeatedly stated he would not return as Jack Bauer, though he read the Legacy pilot script, called it 'really cool,' and said he would be the first person to watch it.

Stephen Hopkins, who directed the original 24 pilot and several first-season episodes, also directed the 24: Legacy pilot, while frequent 24 director Jon Cassar returned to direct 6 of the show's 12 episodes.

With the show's plot involving a presidential election, writer Evan Katz said the writers deliberately kept the storyline neutral regarding real-life candidates since they began writing before the actual frontrunners were known.

Fox partnered with Samsung to release a virtual reality tie-in experience written by Howard Gordon ahead of the series' February 2017 debut.