Co-creator Roy Huggins had previously created the Western series Maverick starring James Garner, and envisioned The Rockford Files as essentially Bret Maverick reimagined as a modern-day private detective.

Huggins' creative involvement with the show effectively ended midway through the first season after he submitted a script rewrite directly to the set without approval; Garner, dissatisfied with the material, then issued a directive that co-creator Stephen J. Cannell, not Huggins, would have final say on all scripts.

In the pilot episode, Jim Rockford's father Rocky was played by Robert Donley and written as more of a small-time grifter, before Noah Beery Jr. took over the role for the series and portrayed a more honest, reliable version of the character.

Tom Selleck's recurring character Lance White, a glamorous rival private eye, was based on Wayde Preston's character 'Waco Williams' from Maverick, whom Preston resembled decades before Selleck; Selleck later became famous as Thomas Magnum in Magnum, P.I.

Officer Todd Billings was played by Luis Delgado, who was both the real-life brother-in-law of series co-creator Roy Huggins and James Garner's longtime stand-in.

Officer Al Mazursky was played by Bucklind Beery, the real-life son of Noah Beery Jr., who portrayed Rockford's father Rocky.

James Garner directed only one episode in his entire 50-plus-year film career, the season-two episode 'The Girl in The Bay City Boys' Club', taking on the assignment only because the scheduled director became unavailable at the last minute.

Garner performed the show's signature 'Rockford turn-around' (or J-turn) driving stunt himself throughout the series, a maneuver involving reversing at speed, yanking the emergency brake to spin the front end, then accelerating away in the opposite direction.

The show went on hiatus in late 1979 when doctors ordered Garner to recuperate from knee injuries, back trouble, and an ulcer caused largely by performing his own stunts for realism; NBC then abruptly cancelled the series and sued Garner for failure to perform.

Garner recounted on The Tonight Show that the studio once paid a carpenter $700 to build a shipping crate for a shoot-out scene on a boat dock, even though shipping crates were already present on the dock.

Rockford's gold Firebird was actually a higher-performance Pontiac Firebird 'Formula' model rebadged and rehooded to look like the lower-tier Esprit, giving the car chase-worthy performance while still appearing to be a car Rockford could realistically afford.

The theme tune, composed by Mike Post and Pete Carpenter, reached number 10 on the Billboard Hot 100 in August 1975 and won a Grammy Award for Best Instrumental Arrangement.

English football club Tranmere Rovers have used The Rockford Files theme as their match walk-out music for over 40 years.

David Chase, who wrote episodes for The Rockford Files including 'The Jersey Bounce' about low-level wannabe gangsters, later created The Sopranos, which included a similar plotline about low-level mobsters in its second season.

The opening answering-machine messages, delivered over Rockford's Ansafone, were a recurring comedic device; 122 different messages were created across the six original seasons, often referencing earlier episodes rather than the current one.

A legal dispute between Garner and Universal over Rockford Files profits lasted more than a decade before being settled out of court in Garner's favor, delaying the character's return until reunion TV movies began in 1994.