The teenage activist is expected to catch a train to Glasgow to join striking binmen on a march through Glasgow during Cop26.
The 18-year-old, who left Stockholm on Wednesday and arrived in London by train on Thursday, joined a Youth Strike to Defund Climate Chaos (YSDCC) protest against the funding of fossil fuels outside the Standard Chartered Bank in London.
Ms Thunberg, who wears single-use facemasks, may have taken up to five trains before she arrives in Glasgow.
One suggested route involves a train from Stockholm to Copenhagen, Copenhagen to Hamburg, Hamburg to Amsterdam, Amsterdam to London and a final train from London to Glasgow.
She is one of thousands protesting across 26 countries and every continent in the world to demand the global financial system stops putting money into the use of fossil fuels.
The protests come just days before global leaders are set to join for the Cop26 UN climate change conference in Glasgow on Monday.
Leaders including Prime Minister Boris Johnson will discuss how best the world can work together against climate change.
The Prime Minister previously said he fears the summit could fail to make the change needed for the environment.
Greta Thunberg joined protesters in London at a Youth Strike to Defund Climate Chaos protest against the funding of fossil fuels outside the Standard Chartered Bank in London
The environmental activist arrives ahead of a protest outside the Standard Chartered financial headquarters on Friday
Ms Thunberg visited the Natural History Museum this morning to celebrate a beetle that was named Nelloptodes gretae in her honour.
Earlier this week Ms Thunberg described herself as ‘silly’ in private, adding that people would not recognise her.
She told the BBC: ‘I’m not very serious in private. I appear very angry in the media but I’m not, I’m too silly. I’m too much maybe. I don’t see myself as a kind of celebrity, I see myself as an activist.
‘I don’t think my own life, my own future is that interesting’.
It comes after Mr Johnson said he was concerned Cop26 might ‘go wrong’.
He added: ‘We need as many people as possible to go to net zero so that they are not producing too much carbon dioxide by the middle of the century. Now, I think it can be done. It’s going to be very, very tough, this summit.
‘I’m very worried because it might go wrong and we might not get the agreements that we need.’
Ms Thunberg with an enlarged image of the minuscule beetle that was named in her honour Nelloptodes gretae at the Natural History Museum on October 29
Flowers outside Lloyds of London in protest to demand the global financial system stops putting money into the use of fossil fuels
The Day of Action protest could be one of the largest climate finance protests in history and will take place at financial centres in London, New York, San Francisco and Nairobi.
Activists will campaign outside branches of Barclays, Standard Chartered, Lloyds of London and the Bank of England, with Ms Thunberg set to join them.
The protests come after campaigners revealed banks have paid £2,754,145,000,000 into fossil fuel extraction since the 2015 Paris agreement where world leaders committed to limit the rise in global temperatures to 1.5C and reach net zero emissions by 2050.
A protester holds a sign reading ‘Lloyd’s insuring the death of our world’ outside Lloyds of London on Friday
Flowers are left outside Lloyd’s of London as protesters urge the company to stop funding use of fossil fuels
Ms Thunberg examines the minuscule beetle that was named in her honour
The International Energy Authority says there can be no further exploration of oil and gas after 2021.
Joseph Sikulu, from Pacific Climate Warriors, said: ‘Financial institutions that continue to invest in dirty fossil fuel projects are also investing in the destruction of our islands and our homes.
‘It’s time for the corporations who have caused this crisis to be held accountable.
‘The science is clear. We need to do everything we can to limit global warming to 1.5C, the survival of our islands depends on that. To get there we need to defund the climate chaos.’