Gang leader Ryan Joseph Black, 29, received the longest term, seven and a half years, with a man described as his "trusted lieutenant" William Johnston, 35, given six years and nine months at Belfast Crown Court on Friday.
Couriers and low level organisers Aiden McPartland, 32, and Mark Mulholland, 27, were handed terms of 22 and 24 months respectively while 33-year-old Anthony McStravick and James Turley, 53, were jailed for 15 and ten months respectively.
A seventh man, 38-year-old Warren Martin was jailed for 13 months.
Belfast Crown Court Judge David McFarland ordered that each man serve half his sentence in jail and half on licenced parole.
He also ordered that two cars seized in the huge police operation, a Ford Mondeo and a BMW 320, be sold, and along with £18,500 seized by police who smashed the smuggling ring, the proceeds should go to the Northern Ireland Cancer Fund for Children.
A major drugs manufacturing operation was uncovered in a city centre flat in 2010 as part of a proactive police probe called 'Operation Saggital' created to disrupt the gang.
In October 2010, Organised Crime Branch detectives seized herbal cannabis worth £900,000 from a lorry and a taxi in the Duncrue Road area of Belfast. Two men were arrested.
Two months later, in December, herbal cannabis worth £500,000 was seized after three vehicles - a lorry and two cars - were stopped at Apollo Road also in the city. Three men were arrested, including the leader of the crime gang Ryan Black.
On the same day, cannabis and cocaine worth £1.1 million was found at an upmarket apartment in Laganview Court, Belfast after it was raided.
It was being used by the gang to store cannabis and process cocaine. Following further enquiries, police arrested another two members of the gang.
They were sentenced at Belfast Crown Court on Friday after admitting their roles in the supply of class A, B and C drugs into Northern Ireland.
Arrested during the October operation was lorry driver Martin, from Windsor Terrace in Coagh, Co Tyrone and taxi driver McPartland, from Deramore Gardens in Belfast.
Black, whose address is barred from being published by order of the judge, was arrested during the December operation and the court heard that at the same time, officers uncovered a cannabis store at Laganview Court and items used to cut and process cocaine including car jacks, cutting agents, boards, scales, knives and industrial blenders.
Lorry driver Turley, from the Ballymore Road in Tandragee, Co Armagh and Mulholland, from Colonsay Park, Ballymena, Co Antrim were also arrested in December as the blocks of cannabis were exchanged.
The drugs had been smuggled into Belfast on ferries from Liverpool and then sent to the apartment to be processed and the court heard that in total, police seized a kilo of class A cocaine, 52,000 illicit tablets, 30 kgs of cannabis and £18,500 in cash.
All the items uncovered in the flat were forensically examined and as well as Black's DNA being found on many of them, scientists also found a profile matching that of McStravick, who is from Ailesbury Road, Belfast. His job had been to cut the cocaine.
Johnston, from Windermere Park, Belfast and Black both pleaded guilty to supplying and possessing with intent to supply drugs in class A, B and C.
Martin, McPartland, Mulholland and Turley all pleaded guilty to supplying or possessing cannabis with intent to supply and McStravick admitted a charge of supplying class A drugs.
A police statement said: "During a parallel investigation in England conducted by East Midlands Special Operations Unit a total of 11 individuals received convictions last year."
"Police believe today's convictions have stopped the flow of drugs into Northern Ireland which was being driven by this organised crime gang."
Organised Crime Branch Detective Superintendent Philip Marshall added: "This was a lengthy and complex proactive investigation into an organised crime gang which was bringing large quantities of controlled drugs into Northern Ireland.
"We have secured convictions against the gang leader and his deputy as well as their couriers and the individual responsible for mixing the cocaine. Working with colleagues in East Midlands Special Operations Unit, we have swept away a web of illegal drug supply covering Northern Ireland and part of England.
"The gang leader, Ryan Black, believed he could direct the activities of the gang from a safe distance and escape the reach of the law. But the investigation by Organised Crime Branch was of such a comprehensive and forensic nature that his plan failed. Both the gang leader and his associates have been made amenable.
"In Northern Ireland we have dismantled a gang responsible for large scale drugs importation."
Civil proceedings in relation to a number of properties which have been restrained as a result of this investigation are now scheduled to begin.