In a statement released immediately after the vote, the office of the former president said "this has been yet another phase of the greatest witch hunt in the history of our Country".
"It is a sad commentary on our times that one political party in America is given a free pass to denigrate the rule of law, defame law enforcement, cheer mobs, excuse rioters, and transform justice into a tool of political vengeance, and persecute, blacklist, cancel and suppress all people and viewpoints with whom or which they disagree," the statement said.
"I always have, and always will, be a champion for the unwavering rule of law, the heroes of law enforcement, and the right of Americans to peacefully and honorably debate the issues of the day without malice and without hate."
In response, the Senate's top Democrat Chuck Schumer said 6 January will forever be remembered as "a day of infamy" in American history.
Taking to the Senate floor after the vote, Mr Schumer called the day of the riot the "final, terrible legacy" of Mr Trump, adding that the stain of his actions will never be "washed away".
In a follow-up tweet, he said Mr Trump's actions during the riot were "antithetical to our democracy".
Republican Senate Minority Leader Mitch McConnell, who voted to acquit Mr Trump, also delivered a blistering speech after the vote condemning the former president's conduct as a "disgraceful dereliction of duty".
"January 6 was a disgrace. American citizens attacked their own government," Mr McConnell said on the floor of the Senate.
He said the pro-Trump rioters had been “fed wild falsehoods by the most powerful man on earth” who was “angry he’d lost an election”.
"There's no question, none, that President Trump is practically and morally responsible for provoking the events of the day,” Mr McConnell said. “No question about it. The people who stormed this building believed they were acting on the wishes and instructions of their president.
"Having that belief was a foreseeable consequence of the growing crescendo of false statements, conspiracy theories and reckless hyperbole which the defeated president kept shouting into the largest megaphone on the planet.
"It was a manufactured atmosphere of looming catastrophe, the increasingly wild myths about a landslide election, some secret coup by our now-President.”
Mr McConnell went on to accuse Mr Trump of “not doing his job” during the riots, accusing him of “watching TV happily” as the demonstrations went on.
"A mob was assaulting the Capitol in his name. These criminals were carrying his banners, hanging his flags and screaming their loyalty to him. It was obvious that only President Trump could end this,” he said.
"Former aides publicly begged him to do so. Loyal allies frantically called. The president did not act swiftly. He did not do his job. He did not take steps so federal law could be executed and order restored. No. Instead, according to public reports, he watched TV happily as the chaos unfolded. He kept pressing his schemes to overturn the election.”
"Later, when the president finally started half-heartedly calling for peace, he didn't call right away for the riot to end. He did not tell the mob to depart until even later. And even then, with police bleeding, he kept repeating election lies and praising the criminals.”
Mr McConnell then, however, went on to justify his reason for voting to acquit, saying the Senate lacked the jurisdiction to punish the former president.
Seven Republican senators voted in favour of the impeachment - Richard Burr, Ben Cassidy, Susan Collins, Lisa Murkowski, Mitt Romney, Ben Sasse and Pat Toomey. As expected, all Democratic Senators voted to convict.
The impeachment charge, passed in January by the Democrat-controlled House of Representatives, stated that Mr Trump had “threatened the integrity of the democratic system, interfered with the peaceful transition of power, and imperiled a co-equal branch of government”.
“He thereby betrayed his trust as president, to the manifest injury of the people of the United States,” the article of impeachment stated.
In his closing argument, House prosecutor Jamie Raskin said Mr Trump’s “dereliction of duty … was central to his incitement of insurrection, and inextricable from it.”
“It’s now clear beyond doubt that Trump supported the actions of the mob…and so he must be convicted. It’s that simple,” he said.
The acquittal follows a chaotic morning in which the Senate unexpectedly voted to call witnesses which could have changed the course of the trial.
It came after details of an angry phone call between Mr Trump and House Republican leader Kevin McCarthy came to light, which appeared to show Mr Trump supporting the Capitol rioters.
The phone call prompted a debate that initially resulted in the Senate voting to allow witnesses, before reversing these changes.
Republican congresswoman Jaime Herrera Beutler, who shared her recollection of the conversation between the pair on 6 January, suggested Mr Trump backed the rioters.
She said when Mr McCarthy asked the president to call off his supporters, Mr Trump replied: “I guess these people are just more angry about the election and upset than you are.”
Lead Democratic prosecutor Jamie Raskin of Maryland asked for a deposition over Ms Beutler’s account, sparking a debate over who could potentially be called to testify.
In the end, both sides agreed there would be no further witnesses or depositions.
Mr Trump’s Twitter account was disabled after the 6 January riots, which saw five people killed and more than 140 injured after hundreds of pro-Trump protesters stormed the Capitol.