The 32-year-old will link up with the squad next week continuing an impressive career in professional rugby.
James played 163 games for Cardiff Blues in two spells that spanned 11 seasons. He also had two years with Exeter Chiefs in the English Premiership.
A powerful, pacy runner, he was capped 12 times for Wales, making his last Test appearance against Scotland in the 2016 Six Nations.
James took a break from the professional game at the end of 2017 and has since spoken openly about his battle with depression.
He returned to rugby last season, making a lone appearance for the Blues and featuring for Merthyr, Pontypridd and Cardiff in the Welsh Premiership.
He is now determined to make another mark on the regional game down west and has been feeling in great shape ahead of the coming season.
“I can’t wait to get started. I am absolutely delighted to have secured this move with the Scarlets,” said James.
“At the end of last season I felt I still had plenty to offer professional rugby, but the opportunity didn’t come at the Blues.
“I have worked hard in the off-season, feel in good shape, and the hunger is there again after a tough couple of years.
“This is an exciting move for me, especially with the way the Scarlets play the game and hopefully I can also offer my experience to the younger players in the squad.
“I want to prove to people that Tom James is back.”
James will join a potent attacking pool of back-three talent at Parc y Scarlets.
“Tom is a high-quality acquisition for us,” said Scarlets general manager of rugby Jon Daniels.
“He has a huge amount of experience in professional rugby, holds the try-scoring record for the Blues, and was in the Wales squad just a couple of years ago.
“As well as being a proven try-scorer, he will give us a powerful, physical presence coming off the wing
“He came in for some fitness testing with us and was one of the top performers in the squad.
“With 14 players in Wales’ World Cup training squad it is going to test the depth of our squad more than any other, so to be able to bring in an international player as cover as well as someone who will be challenging for a starting spot when those players return is invaluable.
“We are looking forward to welcoming Tom to Parc y Scarlets next week.”
