Emergency services, including fire, police and ambulance were called to the pond at around 5.30am on Monday, July 9.
A police spokesman said: "At around 5.30am today the body of a man in his 30s was found in a pond at Haslam Park in Preston. Police are currently at the scene.
"The death is not being treated as suspicious at this stage."
A CSI van remains at the scene.
Police say a file will be prepared for the coroner.