Gibbs' agents Athletes First announced the deal Thursday, hours after he took the field for the first time since the Lions' training camp started. His agents also noted the new contract includes $51.5m (£38.3m) guaranteed for the Pro Bowler.
Two days earlier, Atlanta briefly made Bijan Robinson the NFL's highest-paid running back in history.
Gibbs had been participating in meetings at camp, but Thursday was his first appearance on the field, an indication the Lions and his agents were close to a deal. Gibbs held his right arm high and gave a thumbs-up when asked if an agreement was close as he walked off the practice field.
Gibbs changed his jersey number from 26 to 0 ahead of the 2025 season and rushed for 1,223 yards and 13 touchdowns, and had 77 receptions for 616 yards and five scores.
Colts running back Jonathan Taylor got a two-year, $44m deal earlier Thursday.
On Tuesday, the Falcons agreed to a three-year contract extension with Robinson which, according to Spotrac.com, runs through to the 2030 season, is worth up to $75m (£55m), with the $51m (£37m) guaranteed portion a record for a running back.
Robinson will need to achieve multiple incentives to earn the full $75m (£55m), but even without doing that, the base level three-year $66.75m (£49.6m) deal would have given the 24-year-old the highest annual salary an NFL running back has ever earnt.
The $22.25m (£16.5m) per year took him past the previous high mark of $20.6m (£15.3m) being earnt by Saquon Barkley at the Philadelphia Eagles.
Robinson reposted the NFL's Instagram post detailing the extension on Tuesday morning, writing "God this is for you! Blessings. Love this team and this city!"
