The 22-year-old forward has taken up a two-year deal with the Roosters and will begin training with his new club this week.
Having graduated through the ranks since joining the Panthers four years ago, Smith made his NRL debut in the final round of the 2015 season.
“Chris is a wonderful young man and a footballer with tremendous potential,” Panthers Executive General Manager Phil Gould AM said.
“He has been with our club since his junior rep football days and has made tremendous contributions with every team he has played.
“We are very sorry to lose him but we respect the fact a move to the Roosters gives Chris a great opportunity to advance his career.
“We wish Chris all the best for the future and will follow his development with great interest.”