On the afternoon of 6 January 2021, hundreds of supporters of U.S. President Donald Trump stormed and occupied the U.S. Capitol building in Washington, D.C. Clashes broke out between police officers and protesters after the latter breached the security perimeter and entered the building. Some of the protesters reached the floors of both chambers, and tear gas was used to deter protesters in the Capitol Rotunda. Police officers shot and wounded one person who later succumbed to her wounds at a hospital; at least three others also died due to the violence. Authorities deployed riot police to the Capitol, where officials discovered at least one improvised explosive device (IED). Security personnel removed the protesters from the building using non-lethal measures and arrested 52 people. Multiple members of the Capitol Police were injured during the violence, at least one of whom was taken to a hospital. The U.S. Army activated all 1,100 members of the Washington D.C. National Guard at the request of the mayor of Washington, D.C. National Guard personnel are deployed near the Capitol and other areas in the city. The nearby states of Maryland, New York and Virginia also sent their state National Guard personnel to assist law enforcement officials in the Capitol. A citywide nighttime curfew in Washington, D.C. ended at 0600 local time (1100 UTC) on 7 January, although the mayor has instituted a state of emergency through 20 January. Proceedings of the joint session of the U.S. Congress to ratify Electoral College vote totals were temporarily halted as police officers evacuated members of Congress from their chambers, ushering them to secure locations in the Capitol during the violence. The proceedings were later completed in the early morning hours of 7 January.

Elsewhere in the U.S., gatherings to protest the outcome of the 3 November 2020 election occurred at the Oregon Capitol building in Salem, where protesters clashed with police officers. At least two people were arrested during the event. Additional such demonstrations occurred at the state capitols in Georgia, Kansas, Oregon and Utah.