The candidate for the election on May 5 is Gareth Derrick, a former naval commander, Labour South West announced last week.
He was chosen after a selection process, during which shortlisted candidates were subject to a ballot by local party members.
Mr Derrick has experience of working in the Navy at several senior positions.
Phil Gaskin, Labour South West regional director, said: “I am delighted to announce that Gareth Derrick is the police and crime commissioner candidate for Devon and Cornwall.
“Gareth will be an excellent candidate due to his background in the military and his ability to communicate effectively with all those that he meets.”
Mr Derrick said: “I am very pleased to be Labour’s police and crime commissioner candidate for Devon and Cornwall.”
He said Devon and Cornwall was largely rural with urban areas, and had a more complex police need than many areas, yet the government had cut its funding repeatedly.
“I will spend the coming months setting out the alternative to the people of Devon and Cornwall.”
Conservative Tony Hogg, the current police and crime commissioner for Devon and Cornwall, is not standing for re-election. The Conservative candidate is Alison Hernandez.
Former Teignbridge MP Richard Younger-Ross, who has said he will campaign to abolish the commissioner post, is the Liberal Democrat candidate.