Blackwood, 28, had a brief spell on loan with the Raiders in 2010, and was part of the team that defeated Castleford in the Challenge Cup. His commitments in France finished when Limoux were defeated in the French Elite League Grand Final on May 17.
Raiders Head Coach Nigel Wright said: “Blackwood is a natural right centre which is a position we have had to use a variety of players to fill. The Chairman was well aware of that and also my concerns about the lack of someone who was experienced in that role.
“Blackwood has a good pedigree, including a number of Super League games under his belt, and is familiar with the role I will want him to play. We will take a good look at him in training this week before deciding when he can be pitched into a game.”
Blackwood played in Super League with Crusaders, having come through the academy ranks at Leigh before moving on to Halifax.
Barrow chairman Des Johnston added: “We will continue to try and add to the squad but will not sign players for the sake of it or if it is not a good value for the club.”