Robins coach Craig Sandercock has been scouring the market to replace Shannon McDonnell and teenager Louis Sheriff, who moved to Hull and departed to live in Australia respectively.
And Eden, who is celebrating his 22nd birthday, is the man drafted into Craven Park following a promising Super League campaign with the Giants for whom he made 27 appearances last season.
On this move, Eden, who also made his debut for the England Knights against Scotland last month and has been compared to the world's best full-back Billy Slater by Huddersfield coach Nathan Brown, told the Hull KR website: "It was a pretty big decision for me to leave Huddersfield as I thought I was settled there for the next couple of years.
"Everything happened quickly though and now that it's all been done I'm delighted to be a Hull KR player.
"To know that the club came along and really wanted me on board is a great feeling and I'm looking forward to repaying the faith that Craig has shown in me."