Landri spent the past two seasons in Philadelphia, starting seven games in 2012 for the Eagles.
The Bucs had been in the market for a defensive tackle since mid-March when Roy Miller, who started 14 games last season for Tampa, signed with Jacksonville.
Landri, entering his seventh year, has played for the Eagles, Panthers and Jaguars since entering the league as Jacksonville's fifth-round pick out of Notre Dame in 2007. Landri's biggest season was in 2010, when he started all 16 regular-season games for Carolina and finished tied for fourth on the team with three sacks.
The 29-year-old Landri will join a Buccaneers defensive unit that finished No. 1 in the league against the run last season but was 32nd against the pass.
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