Arsenal great Henry - who was just named new head coach of the Montreal Impact - scored 51 goals for his country, the most of any France player, in a career that saw triumphs at the 1998 World Cup and Euro 2000.
However, Mbappe, still just 20, has already tallied 13 international goals, also winning a World Cup in Russia in 2018.
The Paris Saint-Germain forward has quickly established himself as one of world football's outstanding talents and appears set to dominate for years to come.
Henry certainly believes that will be the case, explaining when asked by Omnisport if Mbappe could break his record: "With Kylian, we say he's young because of his age but he's not really young anymore because of what he does, because of the amount of games he has played, because of his game IQ.
"I often talk about that because we talk about his speed, his dribbles, his goals, and I think we'll talk about it for 20 more years. It's [a long time], I hope for him, but yes maybe 15, 16 years, 20 years if he can.
"Ibra [Zlatan Ibrahimovic] is still playing [at 38]. If [Mbappe] has no injuries, he'll be called up [to] the national team, of course he will.
"So yes, I think he will set the bar very, very high."
Henry is similarly optimistic France can follow up their World Cup triumph from last year with further success at Euro 2020.
He points out Didier Deschamps' men came close at the last European Championship, losing to Portugal in the final on home soil, before excelling further on the world stage - aided by Mbappe's emergence.
"It's very hard [to win consecutive tournaments] because everybody's waiting for you," Henry said.
"It's not easy to do it again, especially at that level.
"Spain did it three times in a row [from 2008 to 2012]. That French generation could have done the back-to-back [in 2016] but sadly [Portugal goalscorer] Eder decided otherwise, so it could have been three in a row.
"What is remarkable with that generation - and especially with Deschamps, who's there to guide them because he lived it as a player - is that people forget that they reached the final of Euro 2016, and then they won the World Cup.
"Now everybody's waiting for the confirmation. That team has talent, they proved it, they played two finals in a row, one lost, one won.
"What this generation is doing is extraordinary and it's good for French football. But yes they can do it [win again]."