The 25-year-old Miller appeared in 15 games (14 starts) for Tampa Bay in 2012, recording 24 tackles. He played 503 snaps, per Pro Football Focus.
The 6-foot-2, 310-pound Miller will help the Jaguars replenish their interior line depth after Terrance Knighton signed with Denver.
In addition, the Jaguars also announced they had struck a deal with Texans free agent defensive back Alan Ball, who notched 21 tackles in 11 games for Houston in 2012. Ball, who has made 22 starts, gives the Jaguars another experienced option in the secondary. He has played both cornerback and safety in the pros.