The Villans managed to seal their Premier League survival with two games left to play following a turbulent campaign.
Despite Villa's struggle for positive results, Okore admits that Vlaar's leadership played a big part in the club staying up.
"I have been really impressed with him – as a defender and as a skipper," he told the Express & Star.
"He's the rock of the defence. Everyone looks up to him. He always works very hard every day at the training ground. He takes responsibility for everything on the pitch."
Okore played just four games for Villa last season before suffering a cruciate knee ligament injury.