Hall, a cornerback from Michigan, was the last of the Bengals' seven draft picks to sign. He missed two practices, on Friday and on Saturday morning, but reported to camp in time for the Saturday night session at Georgetown College.
"Leon is very excited to have this finished and to get on with camp," agent Doug Hendrickson said. "He never wanted to miss any time at all, but he knew the business part had to be handled."
Hall said he had expected to wrap up a deal quickly.
"I didn't think it was going to go past today, so I wasn't too worried too much," Hall said. "Personally, I wasn't paying too much attention to it, but sometimes people would text me or my agent would call me to let me know the updates."
Hall, who was taken 18th overall, set a Michigan record for passes defensed (43) and tied for fourth in career interceptions (12).
"We're excited to have Leon here, and I compliment our management and his representatives for getting the contract finished," coach Marvin Lewis said. "Now it's time for Leon to take advantage of a great opportunity and make us a better football team."
Joseph has not practiced this training camp because of a foot injury suffered during the team's June mini-camp.