The 29-year-old has arrived at the Liberty Stadium following a 14-year stint with the Foxes. He has signed a loan deal until the conclusion of the 2017/18 season as Carlos Carvalhal's side battle to escape from relegation to the Championship.
Leicester City stalwart
King arrives in South Wales after a long and successful period with parent club Leicester City. After joining the Foxes' academy from Chelsea, he has gone on to make 377 appearances for the East-Midlanders.
The Barnstaple-born midfielder developed the reputation as a goal-scorer and has gone on to become the highest-goalscoring midfielder in the history of the club with 62 strikes.
King is also the only player ever to have won the top three English division titles with the same club having played roles in Leicester's triumphs in League One, the Championship and the Premier League.
The Welshman has made 83 appearances in the top-flight since 2014 but has found it difficult this season and has only made nine starts in all competitions for the Foxes.
He will now be vying with the likes of Ki Sung-Yeung, Tom Carroll, Leon Britton, Renato Sanches and Leroy Fer for a place in the Swansea midfield.
Not eligible at the weekend
The Welsh international will not be able to make his debut for the Jacks at the weekend. Swansea travel up to the King Power Stadium for a clash with King's parent club Leicester City. As a result, he will be ineligible so will have to wait until next weekend as the team host high-flying Burnley at the Liberty Stadium.
The Swans will be aiming to build on their fantastic 3-1 victory over Arsenal on Tuesday night.