Holt was released by the St. Louis Rams on March 13 shortly before he was due a $1.25 million roster bonus on March 17.
Holt, a seven-time Pro Bowl selection, ranks 11th on the league's all-time reception list with 869 catches.
The 10-year veteran caught just 64 passes last year for 796 yards and three touchdowns, the fewest scoring catches of his career. His total receptions and total yards were the second-lowest of his career, ahead of only his rookie season of 1999.
The Jaguars are in need of a veteran receiver. The team released troubled receiver Matt Jones last month after he violated a plea agreement from an earlier drug charge. They also released Jerry Porter and didn't re-sign free agent Reggie Williams.