The demonstration will assemble at midday at Portland Place and will then follow a route through Langham Place, Regent Street, Piccadilly Circus, Haymarket, Pall Mall and Pall Mall East before congregating in Trafalgar Square from 2.15pm.
Campaigners estimate 15,000 people will attend the annual demonstration, which is in its third year and is organised to mark UN anti-racism day on 21 March.
Stand Up to Racism has focused this year's march on refugees, a day after the EU agreed a deal with Turkey to return all refugees who arrive in the Greek islands from 20 March.
"More than 10,000 attended the Stand Up to Racism march last year and since then the issue of refugees has gained considerable momentum in the news and became a public issue. We are hoping more than 15,000 will attend today," Ken Olende from Stand Up to Racism said.
Labour leader Jeremy Corbyn supports the protests, the campaign group added. Corbyn's first speech as the opposition leader was at the Stand Up to Racism pro-refugee rally held last September.
TfL have said the march will be facilitated under "phased road closures", meaning that once the protest march has passed through a street it will be immediately reopened for public use.
Protests will also be taking place in the UK in Glasgow and Cardiff, alongside protests in other major European cities such as Paris, Athens, Amsterdam, Vienna and Dublin, as well as another seven cities across Greece.