Kristian O'Leary has left the Swans by mutual consent.
The 32-year-old midfielder, who has made over 300 appearnces during his 15 years at the club, has had his contract terminated by mutual consent so he can now therefore sign for another club as a free-agent.
"Kristian is a rare breed in today's game,'' Swans chairman Huw Jenkins told the club's official website.
"There aren't many players who serve a club long enough to get a testimonial these days, let alone give nearly 15 years service as a professional.
"He's always been an honest and hard-working footballer who has been through everything with this club. I think he's seen it all over the years.
"He's been a part of Swansea City Football Club on a daily basis for a very long time, during which he has always conducted himself as a gentleman and true professional.
"It goes without saying that we thank him for all his efforts and loyalty over the years and wish him and his family well for the future.''