The former France striker and now assistant coach of the Belgian national team is currently on a two-day visit to India.
"It helps massively when you have such people in the league," said Henry on Wednesday.
"What helps more is if you can develop young Indian players who can play alongside these footballing greats and learn about the game. That's what will be amazing," said Arsenal and France's leading goal-scorer," he added.
The ISL has attracted top names like Zico, Roberto Carlos, Lucio, Robert Pires, Freddie Ljungberg, David Trezeguet, Alessandro Del Piero, Elano Blumer, Helder Postiga, Adrian Mutu and Nicolas Anelka among others.
Henry landed in Kolkata on Tuesday morning and witnessed the ISL clash between Atletico de Kolkata and Mumbai City FC, a close encounter that left him impressed.
"I arrived into India and came to see the ISL match in the evening. The game needed a goal, which came late, but other than that it's a good atmosphere here. It was a good game of football. We saw two good goalkeepers and Diego Forlan doing what he does best - putting the ball at the back of the net," said Henry.