There are minor clashes and arrests as a protest calling for Robinson to be released from jail mixes with a Welcome Trump march.
Twelve people have been arrested at demonstrations in support of Tommy Robinson and Donald Trump.
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 unfairly treated.
Despite police efforts to keep the marches separate thousands of protesters from the Free Tommy Robinson event and President Trump supporters descended on Whitehall for a largely peaceful rally near the Cenotaph.
UKIP leader Gerard Batten addressed the crowds and likened Robinson's plight to that of other former political prisoners including Nelson Mandela and even Robin Hood.
Scuffles did break out after the police tried to remove inflatables featuring London Mayor Sadiq Khan's face that officers considered crossed the line.
In Trafalgar Square the removal of a Peppa Pig balloon with Khan's face on promoted angry exchanges.
One man was seen on Sky News hitting a police horse and bottles were thrown at the mounted officers.