Jersey have signed Wasps centre Oli Evans and scrum-half Jack Moates, as well as Ulster duo Ross Adair and Charlie Butterworth for next season.
All four players have agreed one-year deals with the Championship club.
They are the first new signings to be unveiled by the island side as they prepare for their fourth season in English rugby's second tier.
"I'm excited to have secured the services of a clutch of young players who have all had experience with clubs at the top tier of domestic rugby in England and Ireland," said Jersey head coach Harvey Biljon.
"The intention is that these recruits will have every opportunity to earn regular game time which is what they need at this stage of their careers. At the same time they will strengthen our squad as we look to cement Jersey's position as an established Championship club."
Moates, 22, began his career with London Irish, making 13 appearances as a replacement in the Premiership, as well as being dual-registered with London Welsh when they won promotion from the Championship in 2012.
He joined Wasps in summer 2013 and has represented the club in both the European Challenge Cup and LV Cup.
|Jersey's remaining fixtures 2014-15|
|Fri 17 April: Bristol (A) - Championship|
|Sat 25 April: Moseley (H) - Championship|
|Sat 2 May: Guernsey (H) - Siam Cup|
His teammate Evans, who is 25, has yet to make a first-team appearance for Wasps, having come up through the club's academy.
He played against Jersey in pre-season and has been dual-registered with National One club Blackheath.
Ireland Under-20 winger Adair scored on his Pro12 debut last month when he came on as a replacement against Newport Gwent Dragons, with the 20-year-old also playing in seven British and Irish Cup games for Ulster Ravens over the past two seasons.
Back-row Butterworth, 24, has not made a senior appearance for Ulster, but has played in six British and Irish Cup games for the club this season.
The club expect to be able to announce further signings in the coming weeks.