The Waterford born defender will be lining out for the club for the third time in his career.
The Blues have also signed striker Aaron Drinan from Cork City.
The Under 19 player has siged a deal which will keep him at the club until the end of the 2018 season.
Colm Whelan who has scored in his last eight games for the Under 17 team has put pen to paper for the first team also.
Two players have left the club by mutal consent. Gary Delaney and Robin Dempsey have departed the RSC.