The 20-year-old has put pen-to-paper on a contract running until the end of the 2015-2016 campaign.
Dixon is no stranger to life with the Pilgrims, having followed up five appearances on loan from Notts County last season with a further 17 appearances during a three-month loan spell between September and December this season.
He subsequently opted to join AFC Telford United on loan for the remainder of the campaign — but has been recalled and released by County to facilitate his permanent arrival at The Jakemans Stadium.
Dixon is eligible to resume his United career in Saturday’s away clash against Hyde FC.