The 22-year-old, who has signed a two-year deal with the League Two outfit, scored five goals for the Pilgrims last season.
Ainsworth told the club's official website: "Paris is a player we've been watching for a while and he impressed in both games against us last season.
"He's quick and tricky and will add another dimension to our attack. I'm sure he's a player that our fans are going to enjoy watching.
"I'm delighted he's agreed to join us and I'm looking forward to working with him."
A number of League Two clubs had reportedly been monitoring developments.