The eight drugs raids started with the seizure of 3,000kg of hashish in the Arabian Sea in November, followed by 500kg of heroin, hashish and crystal meth in December.
Later in December, two more hashish seizures were made in the Arabian Sea, with 49kg of heroin seized in February.
In March, 2,000kg of hashish was seized in the Indian Ocean, while 224kg of heroin was seized in the Arabian Sea and 2,540kg of hashish in the final raid.
A spokeswoman from the navy said: ‘This achievement is the greatest drugs haul by a Royal Naval unit in recorded history.’
HMS Dragon will now undergo routine maintenance before being deployed later this year in support of aircraft carrier HMS Queen Elizabeth.