Prior to the 2017 season, Bush indicated he wanted one more chance to play in the NFL and felt he still had "a lot left to give" on the field.
Bush, who turns 33 in March, told NFL Network's Dan Hellie and Maurice Jones-Drew on Friday that his career has come to an end.
"I'm done," Bush said. "Yeah, I'm done. I said it. It's not breaking news. I've been saying it. I said it all season long, I said, 'Listen, if I don't play this year, I'm going to retire.' Because I'm not going to spend a whole year off, come back, 33 years old, trying to get back in the league. Listen, once you get to a certain age as a running back, they just start to slowly weed you out."
Bush entered the NFL with the Saints as the second overall pick out of USC in the 2006 NFL Draft and played his first five seasons in New Orleans (2006-10). The tailback went on to play for the Miami Dolphins (2011-12), Detroit Lions (2013-14), San Francisco 49ers (2015) and Buffalo Bills (2016), but he still considers himself a Saint.
"The Saints know I'm coming home at some point," Bush said. "I'm going to come home to retire as a Saint. But yeah, man, I'm done. For sure. I'm done."
Bush finished his last season playing for the Bills with minus-3 rushing yards on 12 carries and 90 receiving yards on seven receptions.
The 6-foot, 205-pound Bush, a former Heisman Trophy winner, played in 134 games and gained 9,088 yards from scrimmage during his career. He finished his career with 1,286 carries for 5,490 yards and 477 receptions for 3,598 yards. He scored 58 career touchdowns -- 36 rushing, 18 receiving and four returning punts.