Former Newport Gwent Dragons scrum-half Nicky Griffiths has become Jersey's third major signing of the summer.
The Welshman, who has previously played for the Ospreys, Cornish Pirates and Doncaster, has represented his country at Under-21 level.
Jersey head coach Ben Harvey said: "He's had some vast experience for someone in his mid-twenties.
"He's very highly rated. He's been playing with the Welsh Sevens and been doing fantastically well for them."
Jersey were promoted to National League One after beating Loughborough Students in the play-offs in May.
Griffiths, 26, who follows flanker Guy Thompson and prop James Ellershaw as Jersey's other new signings, was one of 16 players released by the Dragons at the end of the season.
"We hope that he's a player that's going to add an enormous amount to the squad," said Harvey.
"He possesses a lot of pace, makes good breaks and is defensively very sound.
"We hope that he's going to grow with us and move forward with the club.
"It's a bit of coup. He was being chased by a number of clubs, and we managed to secure his signature."