The Met Police was called to the scene at 9pm on Tuesday following reports of an assault. The London Ambulance Service also attended.
The victim, a male, was taken to hospital but his condition is currently unknown.
A Met Police spokesperson said: “Police were called at 9pm on Tuesday, June 1 to reports of an assault in Hyde Park.
“Officers and the London Ambulance Service attended.
“They found a male suffering from stab injuries.