He caught 49 passes for a team-best 760 yards and six touchdowns as a redshirt sophomore.
ESPN's Mel Kiper Jr. rates Hockenson as the fifth-best tight end available. No. 1 is former Iowa teammate Noah Fant, a junior who declared for the draft before the Hawkeyes' victory in the Outback Bowl over Mississippi State.
Hockenson said in a statement released Monday, the declaration deadline, that "now is the right time" to move on from college.
At least one player from Iowa has been selected in the NFL draft every year since 1978.
"We recognize this is an important decision," coach Kirk Ferentz said in a statement, "and we wish them the very best as they pursue the draft."