The 34-year-old has spent the last two years in the Asia League with Tohoku Free Blades.
Jarrett was drafted by Columbus Blue Jackets in 2001 and he went on to sign for New York Islanders in 2003.
The Islanders assigned Jarrett to their AHL affiliate in Bridgeport at the start of the 2003/04 season and he was called up and appeared in his first NHL game in 2006 against Philadelphia Flyers.
The Canadian has since gone on to ice in Germany, Sweden, Finland and Austria.
Giants’ head coach Adam Keefe said: “In Cole the Giants gain more veteran leadership.
“He is an offensive defenceman that does not shy away from the physical side of the game. His résumé speaks for itself.
“He is a good friend of former Giants Captain Jeremy Rebek and that speaks volumes of the type of person he is.”