White, who re-signed with the Patriots on a two-year deal in the offseason, is on the team's physically unable to perform list. He suffered a hip injury last September that ended his season and required surgery.
White said in a statement posted to social media that "it has been an honor to represent my family, my teammates and the people of New England as a Patriot!"
"Thank you to Mr. Kraft, Coach Belichick, and the entire Patriots organization for giving me the opportunity to live out my childhood dream. To be able to play my entire career for one franchise, in front of the best fans in the NFL, has been a tremendous blessing and honor," he added in the statement.
White, 30, has spent his entire eight-year career with the Patriots, who selected him in the fourth round of the 2014 draft out of Wisconsin.
He played sparingly as a rookie in 2014 when the Patriots beat the Seattle Seahawks in Super Bowl XLIX, but quickly elevated into a key contributor from 2015-2020 -- a stretch in which the Patriots played in three more Super Bowls, winning two.
"James White has always been one of the most reliable and dependable players on the field," Patriots owner Robert Kraft said in a statement. "He's a soft-spoken leader who has led by example ... As great of a player as James has been for us, he's an even better person. He is a man of great character and integrity and earned everyone's respect through his work ethic, professionalism and positive daily demeanor."
His role as the pass-catching back in the Patriots' offense has been vital, as he was selected to the franchise's All-Dynasty and 2010s All-Decade Team.
"James defines the term consummate professional," Patriots coach Bill Belichick said in a statement. "His dependability, consistency, unselfishness and performance under pressure are elite. Combining great intelligence, quickness and elusiveness, James was a perfect fit for our pass offense. While soft spoken, he brought exceptional leadership and competitive toughness to the team. He was a multi-year team captain and one of the most respected, best team players I have ever coached."
White holds three Super Bowl records, all from the team's Super Bowl LI win over the Atlanta Falcons: most receptions (14), most points scored (20) and most touchdowns (3).
A four-time team captain, the soft-spoken White set a career-high and franchise record by a running back for receptions (87) and receiving yards (751) in 2018.
He finishes his career with 381 receptions for 3,278 yards and 25 touchdowns in the regular season, while adding 59 catches for 506 yards and three touchdowns in the postseason.
As a rusher, he totaled 1,278 yards on 319 carries (4.0 avg.) in the regular season, with 11 touchdowns. In the postseason, he had 36 carries for 146 yards (4.1 avg.) and five touchdowns.
White was often referred to as "Sweet Feet" -- a nickname he first picked up as a senior at St. Thomas Aquinas School in Fort Lauderdale, Florida, because those on the team told him to add some flavor to his "plain name."
Quarterback Tom Brady often marveled at White, and on Thursday he posted on his Instagram Story: "Teammate, champion, football player through and through. Congrats on the perfect career @sweetfeet."
The Patriots didn't seem to be counting on White's return in 2022, having signed veteran Ty Montgomery as a free agent in the offseason to potentially fill his "passing back" role. The team also selected two running backs in the draft -- South Dakota State's Pierre Strong Jr. (fourth round) and South Carolina's Kevin Harris (sixth round).