The protests in the US capital came as Mr Trump attacked prominent civil rights campaigner Congressman John Lewis on Twitter
Protesters fearful of a Trump presidency have taken to the streets of Washington DC in defence of minority and immigrant rights.
Led by civil rights activist Reverend Al Sharpton, about 2,000 people braved the rain and freezing temperatures to demonstrate near the Martin Luther King Jr Memorial.
Demonstrators voiced anger over Mr Trump's comments on groups including Muslims and Mexicans - as well as plans to scrap Obamacare health reforms.
The protest also included relatives of several African-American people killed in police shootings, Hispanic group La Raza, Planned Parenthood and LGBT group the Human Rights Campaign.
People carried signs reading "Resist Trump's Hate" and "Tu, Yo, Todos Somos America," which translates from Spanish to "You, me, we all are America."
Until hell freezes over
"We march in the driving rain because we want the nation to understand that what has been fought for and gained, that you're going to need more than one election to turn it around," said Rev Sharpton.
He told Democrats in Congress to "get some backbone" and fight against Mr Trump.
"We will march until hell freezes over, and when it does, we will march on the ice," said Cornell
William Brooks, head of the National Association for the Advancement of Colored People (NAACP).
The incoming president has maintained his pledge to build a wall on the Mexican border, deport undocumented immigrants with criminal records, and restrict Muslims entering the country.
Rehab Alkadi, a 31-year-old mother who came to the US from Syria, said she did not think she could be deported, but added: "Who knows? It's so scary, what Trump says ... He said a lot of things bad about the Muslim people."
Mr Trump also plans to dismantle the Obamacare legislation, which has extended healthcare cover to many poorer people.
Trump attacks civil rights leader
The protests in the US capital came as Mr Trump criticised a prominent civil rights campaigner and politician on Twitter after he said he was boycotting the billionaire's inauguration.
The President-elect said John Lewis was "all talk" and should instead focus on fixing his "crime infested" district.
Congressman Lewis, who represents an area that includes most of Atlanta, is the most high-profile Democrat to snub next Friday's event.
He said he would be avoiding the swearing-in ceremony because the tycoon is not a "legitimate president."
Known for his decades of civil rights work - including alongside Martin Luther King - Mr Lewis said Russia's alleged hacking had helped Mr Trump defeat Democratic candidate Hillary Clinton.
In response, Mr Trump tweeted: "Congressman John Lewis should spend more time on fixing and helping his district, which is in horrible shape and falling apart (not to mention crime infested) rather than falsely complaining about the election results.
"All talk, talk, talk - no action or results. Sad!"
Congressman John Lewis should spend more time on fixing and helping his district, which is in horrible shape and falling apart (not to......— Donald J. Trump (@realDonaldTrump) January 14, 2017
mention crime infested) rather than falsely complaining about the election results. All talk, talk, talk - no action or results. Sad!— Donald J. Trump (@realDonaldTrump) January 14, 2017
Mr Trump's comments have sparked outrage among politicians on both sides in Congress.
The Democratic Party of Georgia called on Mr Trump to apologise to Mr Lewis - and the people of his district.
"It is disheartening that Trump would rather sing the praises of Vladimir Putin than Georgia's own living social justice legend and civil rights icon," state party spokesman Michael Smith said.
Congressman John Yarmuth, a member of the Democratic Party and a former member of the Republican Party, tweeted: "All talk no action, @realDonaldTrump? @repjohnlewis shed blood to secure & protect basic human rights for all. Your ignorance is astounding."