Protesters will gather in front of the BBC broadcasting house in Portand Place and then hold a rally in Trafalgar Square.
In 2014, 10,000 people marched in London for UN Anti-Racism day.
The March 21 date is linked to the same day in 1960, when South African police killed 69 people at a peaceful demonstration against apartheid "pass laws" – an internal passport system designed to segregate the population.
The Stand Up to Racism organization, which organizes the demonstration, filled its social network pages with the "Black Lives Matter" hashtag, popular during anti-racism protests in the United States last year. Over the past few years, most notably in 2014, numerous cases of killings of unarmed black and Latino people by white US police officers have reignited public debate over police brutality and racism.
The activist group also speaks against far right and racist organizations operating across Europe and promoting islamophobia, racism and religious hatred.