The former ‘X Factor’ judge was found guilty at Stratford Magistrates’ Court and speaking after the ruling, Tulisa gave a defiant statement, urging more witnesses to come forward.
She also made a reference to her drugs trial, which collapsed on Monday 21 July.
"This has been a rollercoaster week for me. I never wanted any of this,” she said. "I did not assault Vas J Morgan and I am outraged at this decision. I will be appealing it.
"There are a number of high-profile witnesses who were there and know what happened. I urge them to come forward and tell the truth at the appeal.
"I am determined to clear my name as I have already done once this week.
"I repeat - I did not assault Vas J Morgan. I am innocent."
Tulisa’s assistant Gareth Varey was cleared of using threatening behaviour towards Mr Morgan during the same incident.
As the ruling was announced, Tulisa appeared to mutter: “This is bulls***.” She was ordered to pay total costs of £3020.
Mr Morgan issued a statement following the verdict, which reads: "I'm pleased we can finally put an end to this and move on.
"It's been a difficult time for everyone involved and I'd just like to put it behind me. I've had my character questioned and now feel vindicated by the verdict."
The former N-Dubz star is currently thought to be planning a comeback and on Monday 28 July, BBC3 will screen a documentary, entitled ‘Tulisa: The Price Of Fame’, which charts the run-up to the drugs trial.