Depay has played a starring role in PSV's surge to the Eredivisie title this season and is the top scorer in the league with 20 goals to his name.
The Netherlands international - who also netted six goals in the UEFA Europa League this term - has been heavily linked with a move away from the Philips Stadion.
PSV technical director Marcel Brands revealed on Monday that Manchester United and Paris Saint-Germain are interested in Depay's services, with the Premier League club thought to be the front-runners for his signature.
And former Ajax, Barcelona and Netherlands star De Boer told talkSPORT: "He [Depay] is one of the biggest talents in Europe. He has skill compared to a young Cristiano Ronaldo.
"He is very lively, technically unbelievable, very skilful, very fast, he has a great goalscoring record, he can shoot from every distance - he has everything.
"For me, he is without doubt one of the best talents we have [in the Netherlands]."
Asked about the club that would be best suited to Depay, De Boer added: "I don't want to say which club is more suitable for him, but if he goes to United he knows there is a Dutch coach [Louis van Gaal] there who knows him from the World Cup. That is an advantage."
