James Webb, from Macclesfield, Cheshire, was a civil engineering student at Plymouth University.
Officers pulled Mr Webb from the water at Sutton Harbour early on Sunday morning but he died shortly afterwards.
A police spokesman said officers were treating the death as "unexplained but not suspicious". The spokesman said Mr Webb's family had been informed.
Det Insp Ian Reid said: "This is a tragic incident and we would like to offer our condolences to the family.
"We are trying to establish the circumstances surrounding James' death."
Dr Maureen Powers, Dean of Students at Plymouth University, said: "We were deeply saddened to learn of the tragic death of one of our students.
"Our thoughts first and foremost are with his family, friends, and those closest to him.
"James was a promising student who was close to graduating from his MEng Civil Engineering course just next year, and will be sorely missed by all who knew him.
"We are doing everything possible to support those affected at this difficult and incredibly sad time."
Police have named a man who died after being pulled from a harbour in Plymouth as a 21-year-old student.