Gleeson, 24, becomes Craig Sandercock’s second new signing for 2013, following the recent capture of back-rower Cory Paterson from North Queensland Cowboys.
Sandercock said: “Sean is a player that I’ve been watching for a while and will be a terrific addition to our squad next year. He’s been very impressive for Salford this season and at 24-years-old has the best years of his career in front of him.
“Sean also still has a fair bit of potential to fulfil and I’m confident that he’ll be able to achieve that during his time with Hull Kingston Rovers.”
Gleeson started his career at hometown club Wigan, before moving on to join Wakefield in 2007, where he scored 24 tries in 78 appearances.
He then joined Salford ahead of the 2011 season, but didn’t feature on Sunday as the Reds defeated Hull KR 24-22 at Craven Park.