An athletic, dynamic ball-carrying forward, Feaunati has competed in the Premiership since 1997 as well as being capped by Manu Samoa and will no doubt see plenty of action in the 2003-04 season.
"Isaac adds a massive physical, ball-carrying presence to our pack, which we have been missing since the days of Ben Clarke," said Jack Rowell, Bath's Director of Rugby.
"He is a tremendously experienced player and will bring some much-needed steel to the Bath pack. Without World Cup commitments, Isaac has a great chance to cement his place in the side and, indeed, set the benchmark for those players returning from World Cup duty."
Feaunati – who previously had stints with Rotherham and London Irish – is relishing his arrival at the Recreation Ground.
"I am really looking forward to a fresh challenge with Bath Rugby next season as the club looks to re-establish itself at the top of the Zurich Premiership," he said.
"The opportunity came for me to join Bath and I jumped at the chance. The squad that the management have put together for next season looks extremely exciting and I am looking forward to being a part of that squad. Premiership rugby is a big thing, everyone knows that this is a real big competition."
Feaunati will be available for Bath during the World Cup later this year, having decided to rule himself out of the reckoning for further international honours.
"It was a tough decision, the World Cup only comes round every four years," said Feaunati. "I played in the last World Cup with Samoa so it wasn't a decision I took lightly. I had to think about my family as well, I've got kids and a wife, you've got to weigh up the long-term option."
