The FCS All-American fills a major area of need for the Hurricanes. Top cornerback Corn Elder is gone, along with backup Adrian Colbert, leaving Miami in need of more depth and experience at the position.
Delaney wrote a letter to the Citadel community and also posted his decision on Instagram.
"I am very grateful for everything I have learned here and will continue to grow as an athlete and person," Delaney wrote in his letter. "The Citadel has truly helped me mature and become a better man. The things The Citadel has taught me will never be erased, and I can say have made me a better person. I hope everybody can be happy with the decision I have made and be behind me no matter what."
Delaney leaves The Citadel tied for second in school history with 13 interceptions. He graduates in May, so he is eligible to play right away as a grad transfer.
"The pursuit of Dee from one of the most visible and historic programs in college football is a testament to his work ethic and development over the last four years at The Citadel," Citadel coach Brent Thompson said. "We were supportive of Dee while he came to this difficult decision, and we will be cheering for him next season."
The Associated Press contributed to this report.