Footage of the officer, identified as Eugene Goodman, shows him just steps ahead of rioters as they chase him up a flight of stairs.
Mr Goodman is then seen glancing toward the Senate entrance before luring the men in the opposite direction.
Five people, including a police officer, died as a result of the riots.
Another officer who was on duty during the siege died by suicide this weekend, his family said.
The show of bravery from Mr Goodman, reportedly an Army veteran who spent time in Iraq, comes amid criticism of Capitol police for apparent security failures during the storming of the Capitol.
New York Law School criminal law professor and 20-year veteran of the New York City Police Department Kirk Burkhalter called Mr Goodman's response to rioters "tremendous".
"I don't think there was any type of training that would prepare you for that situation," Mr Burkhalter said.
In the video shot by Huffington Post reporter Igor Bobic, Mr Goodman, who is black, is antagonised by the group of Trump supporters - who are all white men.
The image of Mr Goodman trailed by a mob - some armed with Confederate flags, others with allusions to the Nazi flag - was extremely disturbing, Mr Burkhalter said.
"Police officer, not a police officer, to see a black man being chased by someone carrying a confederate flag - there is something wrong with that picture. That should never happen again," he said.
"It just reeks of everything we need to correct."
Officer Goodman has been celebrated by several members of Congress, with some calling for Mr Goodman to be awarded the Congressional medal of honour for his service.
"As Trump's fascist mob ransacked the US Capitol, this brave USCP officer kept murderous rioters away from the Senate chamber and saved the lives of those inside," wrote congressman Bill Pascal on Twitter.
"Last Wednesday, I was inside the Senate chamber when Officer Eugene Goodman led an angry mob away from it at great personal risk. His quick thinking and decisive action that day likely saved lives, and we owe him a debt of gratitude," wrote Senator Bob Casey on Monday.
Mr Goodman's standoff with the mob came just minutes before authorities were able to seal the chamber, according to reporting from the Washington Post.