The 25-year-old signed a three-year contract after passing a medical on Monday.
The former Spain U21 international joins Swansea in an initial £2million deal from Genoa.
“I’m very happy to be here,” Chico told the club’s official website.
“I know I am joining a club that has been growing over the last few years and is still ambitious to go even higher.
“Having played in La Liga and Serie A, two great leagues, it’s a dream come true to play in the Premier League, one of the best, if not the best, in the world.”
Flores, better known as Chico, also revealed that new Swansea boss Michael Laudrup helped to convince him to move to the Premier League.
“He was one of the main reasons I signed,” he added.
“He knows me as a person and a player, so I was honoured when the call came.
“I believe the manager will be good for Swansea and they have done extremely well to get him.
“Swansea’s way of playing is the same style as he wants to play the game. He is the right person to take this club forward.”
