Vertonghen will go up against his club captain this weekend when Belgium play France in a friendly at the Stade de France and he believes Spurs must resist any attempt to prise Lloris away from north London.
The France goalkeeper and captain has been linked with a move to Manchester United, who could lose David de Gea to Real Madrid this summer.
And Vertonghen, who is Lloris’ deputy at White Hart Lane, told Sky Sports News HQ: “He’s a great guy, great captain, great goalkeeper and a brilliant player for us. He’s the captain, very important and this season he was one of our best players.
“He’s been outstanding for us and if you want to continue growing as a club you have to keep your best players and Hugo is one of them. I hope Tottenham can keep him. It will be a sign for everyone next year that we want to compete in the Premier League.
“We ended the season well in the last two games and we didn’t expect to finish fifth. Hopefully we can continue to push for fourth. We’ve got four big teams ahead of us at the moment but we have to find a way to beat them.”