District Judge John Zani said he was “entirely satisfied” that the material was “grossly offensive”, and that it was intended to insult Jewish people.
The judge, sitting at Westminster Magistrates' Court, said Chabloz's "serious" offences may have passed the threshold for a custodial sentence.
About 20 of Chabloz’s supporters packed into the court's public gallery. There were cries of “Shame” and “Justice” after the verdict was read.
A scuffle broke out in front of the courthouse after the verdict between some of Chabloz’s supporters and anti-fascist campaigners.
About ten police officers were called, and the area was cleared.
Chabloz will be sentenced next month.
Chabloz denied all five counts she faced. District Judge John Zani dismissed two counts of sending obscene material. They were alternate counts relating to the same posts.
Defending the singer, Adrian Davies argued that his client’s songs were not “grossly offensive”, adding that there is no law in England against “so-called Holocaust denial”.
Chabloz was subject to a private prosecution brought by the Campaign Against Antisemitism (CAA).
The charity said it took the decision because the Crown Prosecution Service failed to prosecute her.
CAA said that Friday's verdict “effectively delivers a verdict on incitement on social media and on whether the law considers Holocaust denial to be “grossly offensive and therefore illegal”.
CAA chairman Gideon Falter welcomed the “remarkable ruling”, adding that he hoped it would lead to “a total re-appraisal of how the authorities view antisemitic crime”.
He said: “Essentially this is a ruling on the legality of Holocaust denial and antisemitic conspiracy theories in the UK.
“This is about where the line lies between free speech and dangerous antisemitic incitement.
“This is a huge verdict particularly because there is no specific law against Holocaust denial. The fact that she was found guilty means Holocaust denial is considered grossly offensive.
“It is also a total vindication of the CAA’s approach, in that we had to pursue a private prosecution to get (Chabloz) in front of a court.”
In his written judgment, District Judge Zani said that Chabloz “blames others for the fact that she lost an earlier job on a cruise ship”.
He wrote: “Having considered her evidence in some detail, this court considers that it is not unreasonable to infer that her actions may be driven by her as some form of revenge for the said loss of job.”
Chabloz told the JC that she was fired from her job with the Aida Cruises firm after her employers became aware of an anti-Israel tweet she had posted. She denied that it was antisemitic.
She added that three songs, for which she has been convicted, were “provoked” by her dismissal.
Chabloz will be required to attend a probation meeting on May 31 and appear at Westminster Magistrates’ Court on June 14 for sentencing.
Under bail conditions a curfew was set between 11pm and 4am - except on the nights before her probation appointment and sentencing - and she was ordered not to leave England and Wales.
