The 18-year-old centre or back rower should now stay at Giants until at least the end of the 2018 season.
Huddersfield coach Paul Anderson believes that Wood’s hard work has been rewarded.
“In rugby league you tend to get what you earn,” Anderson told his club’s official website.
“And Sam has done that with his attitude and work in training, which has led to him playing some first grade, where he has not let anyone down.
“He has definitely benefitted from his time with the first team squad, and that particularly now shows when he does play at under-19 level, where he is looked at as a leader and key performer.
“Positionally I think when his body matures and fills out he will end up as a back rower.
“But for now his youthful speed may be needed in the centres for us, and I certainly have no qualms in putting him into the team if he continues to work as hard as he is in training.”
Wood now wants to build on the opportunity that the club have given him to prove himself at a higher level.
“It is a great feeling to have signed an extension,” he said.
“It has been a big step up for me playing some games in the first team and it was great to get that opportunity to play.
“Being around the first-team here has been really good for my development because you learn so much about the details of the game.
“Hopefully I can impress and get a few more games and keep working hard for the 19s this season and be ready for when my time comes.”