Police were called to Fistral Beach, Newquay, on Sunday evening at around 9.45pm, some 15 minutes after HM Coastguard was first informed of an incident in the South Fistral area.
Coastguard rescue teams from Newquay, Padstow and St Agnes, lifeboats from Newquay RNLI and a HM Coastguard helicopter were sent to the scene before two people were recovered from the water.
A spokeswoman for Devon and Cornwall Police said: “Police were called by the South Western Ambulance Service… following reports that two people had been recovered from the water at Fistral Beach, Newquay.
“Emergency services attended and a cordon was put in place, which has since been removed.
“Sadly, a man and a woman were pronounced deceased at the scene. Their families have been informed, and our thoughts are with them at this extremely difficult time.
“A file will be prepared for HM Coroner.”
The long, sandy beach is well-known for being one of the best surfing beaches in Europe and is home to a range of seafront facilities.
The beach has an RNLI lifeguard patrol in place during the summer months, but only between 10am and 6pm.
It hosts an RNLI lifeguard station and is one beach down from the RNLI Newquay Lifeboat Station.
Elsewhere, a man also died at a beach in Sussex, near Pound Road in West Wittering, after police were called on Sunday at about 2.30pm to reports of two men in difficulty in the water.
The men were pulled from the sea, with one being pronounced dead at the scene and the other taken to hospital.
Read more from Sky News:
UK set for fourth heatwave
Berlin terror suspect shot dead
In West Mersea, Essex, a mother and her teenage daughter died in the water last week.
And in nearby Clacton a man was left in a critical condition after three swimmers got into difficulty near the pier on Saturday.
While the exact details of what happened in the new incidents are not yet known, RNLI warned that heatwaves bring a sharp increase in the risk of drowning as more people try to cool off in water.
