Plymouth chairman Sir Roy Gardner believes that Reid is the right choice to get the club back into the Championship following their relegation to League One.
“The Plymouth Argyle Board of Directors are delighted to have secured a manager whose high reputation precedes him,” Gardner told the club’s official website.
“Peter has a wealth of experience after a lifetime in the dressing-room and dug-out which made him the stand-out candidate to progress the club on the pitch.
“We look forward to many years of success together.
“We said all along that we were seeking a man with proven experience who could help us realise our aspirations and ambitions – we want to get back to the Championship and, after that, move on.
“Peter fits that criteria perfectly.
“He is an international manager and player, and, domestically, he has achieved success in both spheres at the highest echelon.
“He also knows how to mix it outside the Premiership, winning lower league titles on the pitch and from the sidelines.
“He is well connected, commands respect, and has a depth of knowledge of the game that few of his peers can match.”