"I've had a better run than I ever could've dreamed of having," Barber told FoxSports.com.
Barber made his retirement official at a 2 p.m. ET Thursday news conference.
"Ronde is synonymous with the Tampa Bay Buccaneers, establishing himself as one of our franchise's iconic players over a 16-year, Hall of Fame-worthy career," said Buccaneers co-chairman Joel Glazer. "When anyone thinks of Ronde, they think of a true professional and leader. He approached every day the same, giving everything he had to make himself and his teammates the best they could be. We will miss him."
The 38-year-old Barber moved to free safety last season after playing his entire career at cornerback. But the Buccaneers' starting free safety job was no longer available after the team signed Dashon Goldson in free agency.
A five-time Pro Bowl selection, Barber finishes his career with 47 interceptions, 205 passes defensed, 1,234 tackles, 28 sacks and 16 forced fumbles in 241 career games.
He is the franchise leader in interceptions and defensive touchdown returns (eight).
Barber's signature moment came in the 2003 NFC Championship Game when his 92-yard interception clinched the Buccaneers' 27-10 win over the Philadelphia Eagles. Tampa Bay went on to beat the Oakland Raiders in Super Bowl XXXVII.
Information from ESPN.com NFC South blogger Pat Yasinskas was used in this report.