Mr Boutcher said he is “very honoured” to be selected to lead the under pressure force.
His appointment was approved by Secretary of State Chris Heaton-Harris following interviews of the final two candidates on Monday.
Assistant Chief Constable Bobby Singleton was also shortlisted for the job vacated by Simon Byrne, who resigned in September after a string of controversies.
Mr Boutcher, who has 35 years’ experience in policing, was previously appointed as the interim head of the service pending the outcome of the interviews for the permanent £220,000-a-year post.
The Policing Board interviewed the two shortlisted candidates at the board’s headquarters in Belfast, before a multi-stage deliberation and selection process.
The interview panel was made up of Policing Board chairwoman Deirdre Toner, independent board member Mukesh Sharma and three political members of the oversight body: Sinn Fein’s Gerry Kelly, the DUP’s Joanne Bunting and Nuala McAllister from the Alliance Party.
Mr Boutcher previously applied to become PSNI chief constable in 2019, but lost out to Mr Byrne.
He was until recently leading Operation Kenova, which has been investigating the activities of “Stakeknife”, the Army’s top agent in Northern Ireland during the Troubles.
The new PSNI chief faces a challenging in-tray, including a budget crisis, dealing with the fall out following a significant data breach in which the personal details of all officers and staff were mistakenly published online, and a critical High Court ruling that said two junior officers had been unlawfully disciplined for their actions at a Troubles commemoration event.
In a statement, Mr Boutcher said: “This position carries great responsibility and is a huge privilege. I look forward to leading the dedicated officers of this exceptional organisation.
“There is much to do and I am fully committed to delivering an outstanding policing service to address the issues which matter most to our communities.
“The officers and staff of the Police Service do an extraordinary job and will have my full support.”