The gangster, who was once the most wanted man in Europe, had denied leading a plot to flood the Channel Island's streets with the illegal drug.
A jury at the Royal Court in St Helier found him guilty of conspiracy to import a controlled drug today after a two week trial.
Warren, 46, from Liverpool, showed no emotion as the jury's unanimous verdict was given after around nine hours of deliberations.
His co-accused Jonathan Welsh, 43, James O'Brien, 45, Jason Woodward, 22, Paul Hunt, 27, and Oliver Lucas, 23, were also unanimously found guilty of conspiracy to import a controlled drug.
The gang aimed to buy 180kg (400lb) of the drug in Amsterdam and transport the consignment by car to the coast of Normandy, France, where it was to be placed on a boat to Jersey.
Police surveillance teams and bugging devices caught Warren and Welsh arranging with underworld associates to obtain and transfer the cannabis haul - and claim his "cut" of the profits.
The jury heard one conversation where Warren described the plot as "just a little starter".
Crown Advocate Howard Sharp, prosecuting, told the jury: "Warren was the senior figure, he was the man at the top who pulled the strings.
"He had considerable clout and influence and we say he orchestrated this conspiracy.
"He was the crucial link between the sale in Holland and the purchasers in Jersey."
Just weeks before the Jersey plot began in May 2007, Warren was released from a Dutch prison where he had served 10 years of a 17-year term for drug trafficking, firearms offences and, later, manslaughter.
The jury was told he was a drug trafficker of "substantial wealth and influence" and he was the only known trafficker to have appeared in the Sunday Times Rich List.
Warren's defence said he knew he was being bugged by the UK's Serious Organised Crime Agency (Soca) and the Jersey Police.
Advocate Stephen Baker, defending, claimed the recorded conversations had nothing to do with drugs and suggested he may have been arranging to buy guns to defend himself from rival gangsters or managing the "many, many" millions of pounds he has made from drug dealing.
Some of the surveillance evidence was obtained illegally by Jersey Police, leading to two years of court hearings before the trial took place.
But British Appeal Court judges, sitting in Jersey, ruled that the illegal recordings should be heard "in the interests of justice".
All six were remanded in custody until sentencing on December 4.
Acting Chief Officer David Warcup, of the States of Jersey Police, said: "The conviction of the men involved in this trial marks the end of a complex police operation, which has seen officers from the States of Jersey Police, the Serious Organised Crime Agency (Soca), Merseyside Police, France, Holland and Belgium working together.
"We hope that the conviction of the men sends out a clear message to others that we will continue to tackle those responsible for the importation of drugs into the island.
"The conviction is also a reflection of the hard work, dedication and commitment of all the officers and agencies involved in this inquiry.
"Tackling serious and organised crime is a priority for the States of Jersey Police. This includes targeting the importation of drugs into the island. In recent years serious organised crime has become increasingly sophisticated and global in its activities.
"If the island is to protect itself from the impact of serious and organised crime and all that this entails, we must remain focused on defeating those who seek to bring crime to the island.
"It is estimated that the recent police operation cost in the region of £500,000, although we have yet to finalise the accounts in relation to this matter.
"Whilst it is appropriate that all costs are fully accounted for, the most important thing is to demonstrate our determination to fight serious crime.
"Anything less than a show of determination will send the wrong message to criminal gangs and leave the island exposed to be exploited by criminals who seek to reap the financial benefits of the lucrative drugs market which exists within the island.
"It will also potentially expose the island to the types of violence which is frequently associated with the drugs trade.
"We remain determined to make sure that this does not happen."
Bill Hughes, director general of SOCA, said: "Serious organised criminals don't suddenly stop just because they have been caught once. That is why when a criminal comes onto SOCA's radar, they stay there for life.
"Curtis Warren was a career criminal for whom prison was a temporary setback. He was already planning his next operation from inside prison, and when he was released SOCA was waiting, watching, and listening.
"Together with our partners in the States of Jersey Police, we've stopped Curtis Warren's plans in their tracks.
"Criminals need to know that this is a different world now - lifetime management is a reality."
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