The NCL Division One side will now benefit from the ex-St Helens, Wigan, Huddersfield, Bradford, Castleford and Wakefield star’s experience as the season reaches its business end.
“I said I’d always play a few games for Cross once I had retired,” the 38-year-old told the Sharks’ official website.
“My good friend Andy Burland said he was returning to play so I thought the timing was right. There’s also a few lads I coached that I wanted to have a run out with.
“This is a bit of fun for me, to play alongside some friends, which is why I started playing, and to play my final games for the club where it started for me.”
Gilmour is currently working as assistant coach at Wakefield Trinity, and Shaw Cross coach Brett Turner is delighted to have him on board in the community game too.
“It is fantastic to have someone like Lee in the team,” he said.
“He coached some of these lads when they were youth players and it will be good for them to get the chance to play alongside him. For some of these lads it’s a dream to be able to play with someone like Lee.
“When it comes to rugby league, he is one of the sport’s most successful players.”