Joeckel inked the deal Saturday, leaving the team with three unsigned picks.
Under the rookie salary cap, the No. 2 pick in April's draft gets a signing bonus near $13.8 million and has a cap number around $3.85 million in his first season.
The Jaguars selected Texas A&M's standout offensive tackle with the second overall pick in April's draft, expecting him to help bolster an offensive line that allowed 50 sacks last season. He immediately moved from the left side to the right, working exclusively with the first-team offense the last two months.
Jacksonville hopes Joeckel and veteran left tackle Eugene Monroe will give the franchise its best tackle tandem since Tony Boselli and Leon Searcy in the late 1990s.