All the talk at Selhurst Park at the moment revolves around Wilfried Zaha, with Manchester United and Arsenal vying for the talented winger's signature.
But 19-year-old Welsh midfielder Williams is back to fitness after an injury-hit season and Holloway feels he is also destined for the top.
"I'd heard of him before I came here but I'd never been down to London to see him play," said Holloway.
"But good gracious me, if that isn't a little David Villa I don't know what is. He's a modern footballer - his balance, his jinkery, his perpetual motion - I didn't realise how good he is.
"The more he plays, the more I want to see him play. He's one of those players I would pay to see myself. The sky's the limit for him."