Coppell also comes in as director of football
Pompey have appointed Richie Barker as their new manager, with Steve Coppell also arriving in a director of football role.
Barker, 38, who has penned a standard rolling contract, arrives following a 16-month spell at Crawley, who he guided to a 10th-place finish in League One last term.
“This is a fantastic opportunity for me,” he said. “I’m very excited to be at this club with its great history.
“Everyone knows how passionate the people of Portsmouth are about their football club.”
Barker’s first managerial post was at Bury. He took over in April 2011 with eight games of the season remaining, winning six in succession to secure promotion from League Two.
He had spells at Sheffield Wednesday, Linfield, Brighton, Macclesfield, Rotherham, Mansfield and Hartlepool during his playing days.
Former Crystal Palace, Manchester City, Brentford, Brighton, Reading and Bristol City boss Coppell, 58, worked with Barker at Crawley.
He said: “It’s a new challenge for me and I’m very excited. Richie asked if I’d like to be involved and I jumped at the opportunity.”
The ex-England international had a distinguished playing career with Manchester United and was part of the side that won the FA Cup in 1977.
Pompey chief executive Mark Catlin said: “I think the board have made a great appointment. The combination of Richie and Steve is just what the club needs at this time.”