Paramedics from the nearby city of Cairns rushed to treat him at the scene but were unable to save him.
Mr Irwin was known for his television show The Crocodile Hunter and his work with native Australian wildlife.
Police in Queensland confirmed the naturalist's death and said his family had been notified. Mr Irwin was married with two young children.
"It is believed that Mr Irwin collapsed after being stung by a stingray at Batt Reef off Port Douglas at about 1100 (0100 GMT)," a police statement quoted by AFP news agency said.
"His crew called for medical treatment and the Queensland medical helicopter responded. However Mr Irwin had died."
The stingray is a flat, triangular-shaped fish, commonly found in tropical waters.
Steve Irwin with his wife, Terri, in 1999
Mr Irwin's documentaries were shown around the world
It gets its name from the razor-sharp barb at the end of its tail, coated in toxic venom, which the animal uses to defend itself with when it feels threatened.
Although deadly, such attacks on humans are a rarity. David Penberthy, editor of the Sydney Daily Telegraph, told the BBC he had never heard of anyone in Australia being killed by a stingray before.
"You know we still at this early stage don't know what type of stingray it was, or, you know I guess given the bloke's track record, whether he was getting up close and personal with it as well," Mr Penberty said.
"Or whether it was just a total freak accident and in the course of making this nature documentary he just ended up being attacked."
Izvor BBC