Terms were not disclosed, but sources confirmed to ESPN that the deal is worth up to $24 million.
Grant is one of the NFL’s fastest players, and his speed figures to play a significant role in creating big plays for the Dolphins in 2019 and beyond.
Grant, a 2016 sixth-round pick, was set to be a free agent after this season. Now he’ll be under contract until 2023.
The diminutive (5-foot-6, 170 pounds) yet strong Grant made a name for himself early in his NFL career as a feared returner. Grant has three career return touchdowns, including two last season.
He has improved as a receiver every year of his NFL career. Grant figures to remain an asset in offensive coordinator Chad O’Shea’s scheme as a vertical, take-the-top-off-the-defense wideout.
NFL Network was the first to report the terms of the deal.
Grant had a career-high 268 receiving yards before missing the last six games of the 2018 season with a calf injury.
This is the second notable extension the Dolphins have made this offseason with a member of their 2016 draft class. They also signed Xavien Howard to a five-year, $75.25 million extension that made him the NFL’s highest-paid cornerback in May.