The 25-year-old began his career at Exeter Chiefs and spent two seasons on dual-registration at the Brickfields before joining permanently in 2014.
When Albion were relegated from the Championship he left to join their Cornish rivals last summer.
"I had a good season at Redruth but feel I have some unfinished business at Albion," Cowan-Dickie said.
"I want to play again for Plymouth and get the club back up into the Championship.
"Albion are a big club and if they get everything right next season there is no reason why they can't get promoted," added the older brother of England and Exeter hooker Luke Cowan-Dickie.
Meanwhile, Plymouth have added eight Exeter players to their squad for the 2016-17 season.
Ed Holmes, Harrison Cully, Jack Maunder and Billy Keast have joined as dual-registered players, while Joe Simmonds, Harry Strong, Will Norton and Paul Davis have agreed deals as part of the Chiefs' academy structure.
Plymouth Albion have re-signed front-row Tom Cowan-Dickie after a season at National Two South side Redruth.