De Ligt captained his side to a 1-1 Champions League quarter-final first-leg draw against Juventus on Wednesday.
He has become one of the most sought-after talents in European football this season and Van Gaal thinks City, Juve or Barcelona would be the best options for his next step.
"I think De Ligt can play in any competition," the former Manchester United and Barça manager told Ziggo Sport.
"In Italy they are the masters of defence, so he can best develop there.
"If I had the chance I would go to Barcelona. They have central defenders who are not too good, so he will play there.
"Or I would go to Manchester City. I don't think the central defenders are that great either, so he'll play there too."
The 19-year-old has been in outstanding form for the Eredivisie club this season, scoring four goals in 46 appearances across all competitions.
Get the best features, fun and footballing frolics straight to your inbox every week.