The English Defence League founder – real name Stephen Yaxley-Lennon – was sued by Jamal Hijazi after he posted two videos containing false slurs on Facebook in November 2018.
Jamal had been assaulted in the playground at Almondbury Community School in Huddersfield in October 2018, in a video that went viral online.
In response, Mr Robinson suggested Jamal was “not innocent” and made the allegations that the teenager “violently attacks young English girls in his school”.
Mr Robinson also wrongly claimed Jamal “beat a girl black and blue” and “threatened to stab” another boy at his school.
At a libel trial in April, Jamal was forced to deny the claims at the High Court, saying the slurs had a “devastating effect” on the lives and him and his family who had come to the UK as refugees from Homs, Syria.
Today, Mr Justice Nicklin ruled Robinson had failed to prove that his comments were “substantially true”, making an order of £100,000 in damages against the English Defence League founder.
“The consequences to (Jamal) have been particularly severe”, said the judge.
“The defendant’s contribution to this media frenzy was a deliberate effort to portray the claimant as being, far from an innocent victim, but in fact a violent aggressor.
“Worse, the language used…was calculated to inflame the situation.
“As was entirely predictable, (Jamal) then became the target of abuse which ultimately led to him and his family having to leave their home, and to have to abandon his education.
“The defendant is responsible for this harm, some of the scars of which, particularly the impact on the claimant’s education, are likely last for many years, if not a lifetime.”
The judge said Robinson’s case “fell woefully short”, and he had even added further allegations during the legal proceedings.
Robinson was also ordered to pay the costs of the libel action, but will not have to pay any money immediately as he is currently bankrupt.
During the trial, Catrin Evans QC, for Jamal, described Mr Robinson as “a well-known extreme-right advocate” with an “anti-Muslim agenda” who used social media to spread his views. She added that Mr Robinson’s videos “turned Jamal into the aggressor and the bully into a righteous white knight”.
The court heard that the teenager had faced “death threats and extremist agitation” as a result of Robinson’s actions, while the judge said the schoolboy who had carried out the initial attack on Jamal had become collateral damage in the media storm.
He said the impact was “immediate and stark” for the boy, with his family having to move out of their homes on safety grounds.
“It is hardly surprising if (the boy) regarded (Robinson) as something of a saviour - someone who was prepared to help him in what must have been a low and very frightening point of his life.
“With the benefit of hindsight and maturity, (he) may yet come to reflect on whether he has actually been helped by (Robinson).”
The judge today also imposed an injunction on Robinson, preventing him from repeating untrue allegations against Jamal.
The court heard the activist has already taken part in a film about the incident, which may now be broadcast in the US.