Reports in Italy this week suggested that Napoli coach Rafael Benitez was preparing to make an offer after being impressed by the defender during the Italian club's UEFA Europa League meetings with Swansea.
Williams, who is out of contract at the end of the end of next season, has long been linked with a transfer to Arsenal, but a switch to Serie A could tempt him.
His agent, Peter Smith, however, insists that talk of a move to Italy is just speculation at present.
"There has been talk of meetings with the club or with Rafa Benitez, but there's no truth in that at the moment," Smith told Napoli Calcio Live.
"Clearly we are talking about a great club with an international level manager, so we are ready to talk to Napoli if a call were to come.
"However, until the possibility becomes concrete, there's no point talking about it."
Williams has become one of the Premier League's most consistent defenders following his arrival at Swansea from Stockport County in 2008.
Since Swansea were promoted in 2011, the Wales international has played an integral role in maintaining the club's top-flight status.
The 29-year-old also captained Swansea to victory in the final of the League Cup last season.
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