The delivery driver admitted in court on Wednesday that he had unleashed a foul-mouthed tirade and was fined £425. He was told to pay further costs of £85 and a £15 victim surcharge, London's Metropolitan Police said.
Scanlon launched his abusive rant during an English second-tier Championship match at Millwall's Den ground in south-east London on November 18.
Allegations of racism later appeared online before Sky aired the incriminating footage.
Millwall Football Club said it was "appalled" by the clips, while captain Danny Shittu said he was "deeply saddened" by what he saw in the documentary.
The club promised to ban any individuals for life if they were found guilty. It had barred Scanlon for life even before the criminal case, it said in a statement.
Scanlon, from Enfield, north London, was accused of using threatening, abusive or insulting words likely to cause harassment, alarm or distress. He was sentenced at Bromley Magistrates' Court.
Millwall have long had a reputation among rival English clubs for violent and racist fans, although Lions officials have tried hard to rid the club of their unwanted supporters.