Protesters have unfurled five 20m-long banners opposite the US Embassy to "resist" the US president's "trashing of human rights".
Amnesty International's banners on Vauxhall Bridge say “Resist sexism”, “Resist racism”, “Resist hate”, “Resist cruelty” and “Resist Trump”.
Kate Allen, the charity's UK section director, said: “Trump has presided over two-and-a-half years of utterly shameful policies.
“Locking up child migrants, imposing a discriminatory travel ban, decimating global funding for women’s rights and withdrawing from global human rights bodies... We need to resist Trump’s trashing of human rights."
The Amnesty stunt is the first of several protests expected during Mr Trump's three-day visit.