European bison were released into woodland near Canterbury in July as part of a rewilding project to help restore the area to its natural state.
The Hollywood star shared an image of the bison to his 55.6 million Instagram followers.
It was the first bison to be born in the UK wild in thousands of years.
The actor – who describes himself as an environmentalist – frequently uses his social media platform to comment on issues related to climate change.
In the post, DiCaprio describes the animals as “ecosystem engineers” as, through their natural behaviour, “create light and space for other wildlife to thrive.”
Bison clear undergrowth, allowing other plants and insects to move in. They also de-bark conifers, allowing native species to flourish, and their moulted fur provides insulating material for nesting birds.
The rewilding project, led by Kent Wildlife Trust and the Wildwood Trust, is taking place in West Blean and Thornden Woods – one of the largest areas of ancient woodland in the UK, with parts of it over 1,000 years old.
Quoted in the post, Mark Habben, director of zoo operations at Wildwood Trust, said it was hard to imagine “anything could come close to the elation we felt” when the bison took their first steps just weeks ago.
“But here we are celebrating the arrival of a bison calf,” he added.
DiCaprio, who is a UN climate change representative, has donated millions of dollars to environmental organisations and attended COP26 last year.
He is best known for films including Titanic, The Revenant, The Wolf of Wall Street, Django Unchained and The Great Gatsby.