Bale has been in superb form for Spurs this season, with a sensational goal against West Brom on Sunday cementing a top four Premier League position - while Bellamy's side are 10 points clear at the top of the Championship
And Swansea skipper Williams feels the return of the 33-year-old has "lifted" Chris Coleman's squad as Bellamy prepares to make his first international start for nine months against Austria on Wednesday night.
"I don't think there is a better pair of wingers anywhere than [Gareth] Bale and [Craig] Bellamy," Williams told reporters.
|5/1||Gareth Bale is 5/1 to score the first goal when Wales take on Austria with Coral|
"In the past, opposing teams may have just looked to concentrate on trying to stop Gareth. They can't do that any more, because they have to think about the threat offered by Craig, too."
Wales suffered a poor run of form in 2012; despite beating Scotland, they lost their other three World Cup 2014 qualifiers against Belgium, Serbia and Croatia to leave slim hopes of qualifying for the tournament in Brazil.
However, Williams feels the return of Bellamy alongside Bale will help the team to turn the Dragons' fortunes around in 2013.
"We have missed [Bellamy] in the last few games, to be honest," he added. "We were just waiting for him to come back when the time was right for him and his situation and we are pleased that is tonight [Wednesday].
"You can tell the whole squad has been lifted a bit by his presence. He has given us a big boost, although none of us players spoke about him retiring.
"Craig seems happy and relaxed. He is a top-quality player and, with Gareth Bale, gives us something different."