The former California governor likened Wednesday’s violence to that of the Kristallnacht, or the Night of Broken Glass, during which Jewish property was destroyed in Germany in 1938.
He said that rampage was carried out by the “Nazi equivalent of the Proud Boys”, referring to the US far-right extremist group.
In a seven-minute and 39-second video posted on his Twitter account, the 73-year-old actor said: “Wednesday was the Day of Broken Glass right here in the United States.
“The broken glass was in the windows of the United States Capitol.
“But the mob did not just shatter the windows of the Capitol, they shattered the ideas we took for granted.”
He said the violent mob of Trump supporters had “trampled the very principles” on which the country was founded.
Five people, including a Capitol police officer, died as a result of the siege, which took place as Congress was tallying the Electoral College votes to confirm Democrat Joe Biden won the election.
Schwarzenegger, who was born two years after the end of the Second World War, spoke about the dangers of intolerance and his childhood in Austria.
He said he grew up surrounded by “broken men drinking away their guilt” for their participation in the “most evil regime in history”.
“It all started with lies, and lies, and lies and intolerance,” he said.
“So being from Europe, I have seen first-hand how things can spin out of control.”
He accused Trump of seeking a coup following the results of a “fair election” by “misleading people with lies”.
“My father and my neighbours were misled also with lies. And I know where such lies lead,” he said.
“President Trump is a failed leader. He will go down in history as the worst president, ever.”
The Terminator star said he believed the United States would “come out stronger” despite the events of recent days because “we now understand what can be lost”.
“We need to heal, not just as Republicans or as Democrats, but as Americans,” he said.
His comments come as the Democrats’ push to quickly impeach Trump gained support over the weekend, with Republican Senator Pat Toomey stating he believed the president had committed “impeachable offences”.