Michaela McCollum and Melissa Reid who had been working in Ibiza this summer, had previously claimed they were coerced into carrying the drugs by Colombian drug lords who kidnapped them at gunpoint.
They said theywere forced to board a flight from Lima to Spain with 24lb of cocaine in food packets hidden inside their luggage when they were arrested.
So far they have been held at the notorious Virgen de Fatima prison in Lima.
Their guilty pleas at the end of September came on the same day that the UN declared that Peru has now overtaken Colombia as the world's number one coca leaf producer, the raw material of cocaine.
According to a report by the United Nations Office on Drugs and Crime, coca plantations in Peru covered 60,400 hectares last year.
Michaela McCollum, from Dungannon, Co Tyrone, and co-accused Melissa Reid, from Lenzie near Glasgow, were sentenced to six years and eight months by Judge Pedro Miguel Puente Bardales in what was described as a "brief process".
Judicial spokesman Daniel Vega said: "The women were very calm as the sentence was handed down at the court in the Sarita Colonia prison.
"They will now begin serving their sentence in the Santa Monica prison.
"It is still not clear whether they will be able to serve part of their sentence in the UK - the judge said that was not a decision for the court and they would have to reach an agreement with the prosecution."
At an earlier hearing, Melissa Reid, from Scotland, and Irish-born Michaella McCollum pleaded guilty to attempting to smuggle £1.5 million worth of cocaine out of Peru.
Today they were told by a Peruvian court they will both serve six years and eight months in jail.
Michaella McCollum and Melissa Reid, who pleaded guilty to attempting to smuggle cocaine out of Peru in September, have both been jailed for six years and eight months.
Alison Wood from the Whale and Dolphin Conservation group has condemned the practice of using dolphin meat as shark bait as "wasteful and barbaric".
In an interview with ITV News, she said it was completely unnecessary to butcher the animals in this cruel, inhumane way.
"You can use fish guts, and all sorts of things to bait your hook, you don't need to use a sentient, intelligent animal like a dolphin. It is an awful waste. We are talking about a highly intelligent, social, feeling animal, and to see them hunted like this, is barbaric.
Getting the shocking footage of 'the world's biggest dolphin slaughter' meant enduring grim conditions, and almost getting shipwrecked.Read the full story ›
ITV News has obtained footage of dolphins being harpooned hundreds of miles off the coast of Peru and used as bait to hunt sharks.Read the full story ›
Slaughtering dolphins at sea is a cheaper alternative to other forms of bait for sharks, and the method of killing, harpooning, means that the dolphin can bleed for up to 15 minutes. The blood of the dolphin, then attracts sharks.
The illegal slaughter of dolphins for use as bait to hunt sharks is "an open secret" within fishing communities across Peru, according to marine conservation group Mundo Azul.
Working undercover with the group, British journalist Jim Wickens spent a week on board a shark fishing boat 100km off the coast of Peru, enduring rough seas and a near-death shipwreck incident in order to film the hunt.
For more than a decade scientists and environmentalists have been warning of a mass slaughter of dolphins around Peru.
Hundreds of fishing boats have been accused of killing the animals and using their fatty bodies as bait to catch sharks.
The killings, two or three per hunt, by hundreds of fishing boats around the country, add up each year to make it the biggest illegal slaughter of dolphins in the world, according to environmentalists.
ITV News has obtained footage that shows fishermen harpooning dolphins for bait. It's the first time this secret hunting has been filmed.
Science Editor Lawrence McGinty's report contains images you may find disturbing.
The footage, shot undercover by British journalist Jim Wickens, shows the hunting taking place, hundreds of miles off the coast of Peru.