The 32 year old will stay at the Liberty on loan until January with an option to extend the move until the end of the season, and is delighted to be back at the club.
“I can’t wait to get back,” Trundle told BBC Sport Wales.
“Bristol City were in the Championship [Swansea were still in League One in 2007] and I thought it was the right time to move but in football things change.
“Either they don’t play your type of game or you don’t fit in in within a certain squad and you’ve got to get on with it because it happens to the best players in the world sometimes.
“Hopefully I can kick-start myself again at the club I love.”