The demonstrators, carrying banners saying “Covid1984” and “Flu d’etat”, chanted “Take your freedom back, take off your masks” as they marched through the West End.
Officers were out in force and the Metropolitan Police later said 10 people have been arrested so far at the Stop the New Normal protest.
“This protest is no longer exempt from the regulations and we are asking demonstrators to leave,” the Met said on Twitter.
“There is disruption on Westminster Bridge as officers continue to disperse crowds.”
By 2.30pm the protesters were outside New Scotland Yard and reportedly heading towards Parliament Square.
Officers were deployed outside Buckingham Palace as large crowds of protesters gathered on the steps of the Queen Victoria memorial opposite the palace gates with banners and placards, calling for “freedom”.
Piers Corbyn, brother of former Labour Party leader Jeremy Corbyn, also attended the protest.
Once at Parliament Square, the protesters likely had company in the form of a pantomime cow and a group of chlorinated chickens, who gathered on Saturday to protest against a proposed trade deal between Britain and the US.
Demonstrators also included a Donald Trump impersonator holding a syringe labelled “hormones” as they called for opposition to the lowering of UK food import standards.
Around 50 people were in Parliament Square in Westminster for the protest, organised by the Stop Trump Coalition, with War on Want Banners and demonstrators playing music and dancing.
It comes with just over a week to go before the US election.
Organisers said any negotiated deal would be a “horror story” and a serious threat to the NHS, UK food standards and democracy.
“Donald Trump’s administration has been one of the most racist and toxic in American history, from the brutal repression of Black Lives Matter protests, the Muslim ban, the torture of migrants and climate change denial,” they said.
“None of this has deterred the UK Government from trying to deepen our relationship with the US through a trade deal.
“Boris Johnson has made it clear that he wants a deal with the US – and Donald Trump has said that everything is on the table.”
Asked if she opposed the lowering of UK food import standards, Daisy the pantomime cow nodded and mooed.
Armed police officers have now dispersed the large crowds of anti-lockdown protesters at Trafalgar Square following a march through central London.