Anjem Choudary was convicted at the Old Bailey court in London on July 28 but the judge had imposed a reporting ban while a linked trial of Choudary's associate was ongoing.
"You have been convicted by the jury of offences which you must expect to result in sentences of imprisonment," Justice Holroyd told the 49-year-old preacher.
"It is true that you have complied with the conditions of your bail. I am afraid however, it has been an evidently grudging compliance and you have made your disregard for the court and its processes abundantly plain throughout these proceedings," the judge said.
The duo face up to 10 years in jail for inviting support for a proscribed outfit and will be sentenced on September 6.
More From This Section
"Terrorist organisations thrive and grow because people support them and that is what this case is about. Do not confuse that with the right of people to follow the religion of their choice or to proclaim support for a caliphate," Prosecutor Richard Whittam told the trial.
Just before his conviction, he told Sky News: "If you look at my speeches, I have said the same thing for 20 years. For me, it is a matter of worship.
"If people are implementing the Sharia, then I cannot shy away from what the divine text says in relationship to that. If you cannot say when you believe in something and you cannot share that view, then you don't really have freedom to express yourself in this country."
He had been arrested last year and been in and out of prison after breaching his bail conditions.
Commander Dean Haydon, head of Scotland Yard's counter terrorism command said: "We have a key individual here in the UK posting vast amounts of information on social media that is radicalising individuals in the UK. Part of that information encourages them to travel to Syria. His mistake was pledging an oath of allegiance. That was the key piece of evidence that tipped him over the line for a terrorist offence."
One of the Bangladeshi attackers, who killed 22 people during an assualt on a Dhaka cafe on July 1, was also a follower of Choudary on social media.