A man has died after a shark attack in the southern Great Barrier Reef.

The 23-year-old was flown to Gladstone Hospital with life-threatening injuries late yesterday.

He had been swimming with a group of friends and was bitten as he swam back to their charter boat moored off the shore of North West Island.

He died from his injuries just after 10pm on Monday.

It is the third attack in the area in as many months.