The Dutchman added another season to his loan move from Villarreal on Saturday.
"I had a great year at Swansea, the people around the club and the fans treated
me well," De Guzman told the club's official website.
"It was not just the results we had; it was more about showing we can also compete with the big teams. We played better against the bigger teams. We did very well - we were very creative. We really put Swansea on the map."
De Guzman enjoyed a productive season with the Welsh team in 2012-13 and forced his way into the Netherlands national side.