Former English Defence League leader Robinson was arrested in May and jailed for 13 months for contempt of court.
He had been filming people involved in a Leeds trial and broadcasting the footage on social media while court proceedings were active.
Thousands of people marched calling for Robinson to be freed from prison as, despite Robinson pleading guilty in court, they believe he has been badly treated.
One demonstrator was seen on Sky News hitting a police horse and there were other minor clashes.
There were also two other marches nearby: an anti-fascist march and a Welcome Trump march, all accompanied by a heavy police presence.
They came a day after an estimated 100,000 people marched through London opposing the visit of the US president.
One woman was arrested on suspicion of violent disorder, two men were arrested on suspicion of public order offences, one man was arrested on suspicion of fireworks offences.
Eight men were arrested on suspicion of assault at Storey’s Gate, Westminster.
The Metropolitan Police said Trump supporters were due to leave the US Embassy and meet Robinson fans on the way to Whitehall, but ordered both must depart Temple Place and follow a strict route after “serious violence” at a march last month resulted in five officers being injured.
More protest against Mr Trump’s visit to the UK took place on Saturday as the president spent the day playing golf in Scotland.