Rhodes, a Yale Law School-educated former army paratrooper and disbarred lawyer, was accused by prosecutors during an eight-week trial of fomenting a plot to use force to block Congress from certifying President Joe Biden's election victory over Trump.
The rarely used, Civil War-era charge of seditious conspiracy calls for up to 20 years behind bars.
He was the best-known of the five defendants in the most significant of the numerous trials arising from the deadly January 6, 2021, Capitol riot. One co-defendant, Kelly Meggs, was also found guilty of seditious conspiracy on Tuesday, while three others - Kenneth Harrelson, Jessica Watkins and Thomas Caldwell - were acquitted of that charge.
US District Judge Amit Mehta has presided over the trial. The jury deliberated for three days.
Rhodes, who wears an eye patch after accidentally shooting himself in the face with his own gun, is one of the most prominent defendants of the roughly 900 charged so far in connection with the attack.
Rhodes in 2009 founded the Oath Keepers, a militia group whose members include current and retired US military personnel, law enforcement officers and first responders. Its members have showed up, often heavily armed, at protests and political events around the United States including the racial justice demonstrations following the murder of a black man named George Floyd by a white Minneapolis police officer.
Prosecutors told the trial that Rhodes and his co-defendants planned to use force to prevent Congress from formally certifying Biden's election victory. Meggs, Watkins and Harrelson entered the Capitol clad in tactical gear.
The defendants was were accused of creating a "quick reaction force" that prosecutors said positioned at a nearby Virginia hotel and was equipped with firearms that could be quickly transported into Washington if summoned.
Fifty witnesses testified during the trial. Rhodes and two of his co-defendants testified in their own defence. They denied plotting any attack or seeking to block Congress from certifying the election results, though Watkins admitted impeding police officers protecting the Capitol.
Rhodes told the jury he had no plan to storm the Capitol and did not learn that some of his fellow Oath Keepers had breached the building until after the riot had ended.
Prosecutors during cross-examination sought to paint Rhodes as a liar, showing him page after page of his inflammatory text messages, videos, photos and audio recordings. These included Rhodes lamenting about not bringing rifles to Washington on January 6 and saying he could have hanged US House of Representatives Speaker Nancy Pelosi, a Democrat reviled by the right, from a lamppost.
Watkins, a transgender woman who fled the US Army after being confronted with homophobic slurs, and Caldwell, a disabled US Navy veteran, also chose to testify.
Watkins admitted "criminal liability" for impeding police officers inside the Capitol and apologised. At the same time, Watkins denied planning to storm the building and instead was "swept up" in events.
Caldwell, who like Rhodes did not enter the Capitol building and never formally joined the Oath Keepers, tried to play down some of the inflammatory texts he sent in connection with the attack.
Four other Oath Keepers members charged with seditious conspiracy are due to go to trial in December. Members right-wing group the Proud Boys, including its former chairman Enrique Tarrio, are also due to head to trial on seditious conspiracy charges in December.
