The Norwegian tourists were spotted unconscious in the water late on Thursday afternoon local time, police said.
Lifeguards pulled the pair, and three others in their group, from the water. A 69-year-old man could not be revived.
Sydney's best-known beach is well patrolled by lifeguards and drowning deaths are rare.
"CPR was immediately commenced on the man but despite the best efforts of all those involved, he was unable to be revived," Surf Life Saving New South Wales said in a statement to the BBC.
A 66-year-old woman remains in a critical condition. Police said she was related to the man who died, and both were from Norway.
Sydney's Daily Telegraph reported the group may have been knocked off their feet by a wave.
The death will be investigated by a coroner.
It was the second drowning in 24 hours in New South Wales, following the death of a man on the state's north coast.
A man has died and a woman is critically injured after being pulled from the surf at Sydney's Bondi Beach.