Sources told the NFL Network that it's a three-year deal worth $41.25 million, with $27 million fully guaranteed. The team hasn't confirmed the financial terms of the deal.
"Donovan has been a valuable player and a model of durability since we drafted him four years ago," Buccaneers general manager Jason Licht told the team's official website. "We always aim to develop our players and reward them for their productivity and reliability, so keeping Donovan as a Buccaneer was a major priority for us this offseason. Donovan's presence ensures continuity at one of our most crucial positions on the offensive line and I know our coaching staff is eager to begin working with him."
Smith is only the second player in Buccaneers franchise history to start every contest in his first four seasons. Tampa Bay selected him in the second round of the 2015 NFL Draft out of Penn State.
Smith signed the new contract eight days before the NFL's new league year begins. He could have become an unrestricted free agent March 13.
The Buccaneers also re-signed linebacker Devante Bond, the team said Tuesday. He could have become an unrestricted free agent.
Bond joined the Bucs as a sixth-round draft choice out of Oklahoma in 2016. He has played in 25 games (six starts) over the last two seasons. He had 22 total tackles in 11 games (four starts) in 2018.