Defender Jack Sparkes joins Portsmouth on a 2-year deal with the option for a further 12 months to be taken up at the end of that contract.
The 22-year-old arrives at Fratton Park having left Exeter City at the end of last season.
Sparkes was born in Exmouth and stands at 5 foot 10 inches. He is a defender who is predominantly used to playing on the left-hand side of the back 4.
During his time at St. James' Park, Sparkes racked up 150 appearances for The Grecians and enjoyed loan spells away at Chippenham Town, Salisbury and Torquay United.
Blues boss John Mousinho said: "Jack's an exciting talent who enjoyed a huge amount of success in helping Exeter get promoted to League One a couple of seasons ago.
"We think that he's ready to kick on, fitting the age and profile of players that we're looking to bring to the club and develop.
"He's a really versatile left-sided player and has good attacking qualities that compliment what we already have in the building.
"Jack's still only young, but played a lot of games for Exeter last season in a side that performed really well at this level.
"So he's already had plenty of experience despite his age. There's a lot of promise there and we're delighted to welcome him to Pompey."