"Based on the evidence, the Court finds it more likely than not that President Trump corruptly attempted to obstruct the Joint Session of Congress on January 6, 2021", the statement said.
The ruling also allowed the House Select Committee investigating the Capitol riot to see emails written to Trump by one of his former lawyers, John Eastman.
"Dr. Eastman and President Trump launched a campaign to overturn a democratic election, an action unprecedented in American history", Carter wrote. "Their campaign was not confined to the ivory tower - it was a coup in search of a legal theory".
The judge's decision comes after the Select Committee argued in its filings that the former US president and his allies engaged in "criminal conspiracy" to prevent Congress from certifying the results of the 2020 presidential election. Trump, who has been claiming "election fraud" since Joe Biden's victory, has vehemently denied the accusations.
Judge Carter has no power to weigh criminal charges against Trump, and neither has the January 6 panel. It is up to US Attorney General Merrick Garland to decide whether to charge the ex-president.
Neither Trump nor Eastman have immediately commented on the ruling.