The Canadian-born midfielder moves to Swansea in search of playing time after riding the bench at Villarreal.
The 24-year-old joins coach Michael Laudrup at the English Premier League side on a one-year loan deal after having played under Laudrup at Spanish outfit Real Mallorca during the 2010-11 season.
De Guzman transferred to Villarreal ahead of the 2011-12 La Liga campaign, and after having made several appearances in the early stages of the season, he found himself increasingly on the bench or not in the matchday roster at all.
"I didn't get much game time when the new coach came in,'' De Guzman told the Swansea official site. "It was a frustrating time for me.
"I just want to play football on a regular basis again. I'm fortunate that I will be working under a good coach (Laudrup) at Swansea who lets you be free and allows you to do what you do best."De Guzman - a native of Scarborough, Ontario - remains eligible for the Canadian national team despite having represented the Netherlands at the youth level.
The former Feyenoord starlet recently re-stated his desire to don Dutch colours at the senior international level, even though his older brother Julian - a stalwart on the Canada squad for the past several years - had previously said that Jonathan was looking into pulling on the Maple Leaf.