"After close review of recent Tweets from the @realDonaldTrump account and the context around them -- specifically how they are being received and interpreted on and off Twitter -- we have permanently suspended the account due to the risk of further incitement of violence," Twitter wrote in a statement.
Trump's final tweet said he would not be attending the inauguration of President-elect Joe Biden.
Hashtags for "TrumpBanned" and "Thank you Twitter" quickly rose to the top of the social media site in the wake of the permanent suspension.
Hours after his suspension, Trump released a statement criticizing the ban, and teasing a possible new platform.
"I predicted this would happen," he wrote in part. "We have been negotiating with various other sites, and will have a big announcement soon, while we also look at the possibilities of building out our own platform in the near future. We will not be SILENCED!"
"Twitter is not about FREE SPEECH. They are all about promoting a Radical Left platform where some of the most vicious people in the world are allowed to speak freely," he added.
Trump had attempted to post the same statement on Twitter, using the official @POTUS account, but the platform deleted the thread, saying users who are banned cannot post from other accounts. The @POTUS account, rarely used by Trump himself over the past four years, will be transferred over to the Biden administration following his inauguration.
The blog post from Twitter announcing the ban cited the events of Wednesday's raid on the U.S. Capitol as a reason for the suspension. Trump's account had been temporarily suspended in the wake of the rioting, but warned the president another violation of its terms of service would result in a permanent ban.
"In the context of horrific events this week, we made it clear on Wednesday that additional violations of the Twitter Rules would potentially result in this very course of action," the company wrote.
Five people died in the rioting at the Capitol on Wednesday, including one police officer, just hours after Trump held a rally and urged his supporters to march to the Capitol.
"We're going to walk down to the Capitol and we're going to cheer on our brave senators and congressmen and women and we're probably not going to be cheering so much for some of them," he said at the rally. "Because you'll never take back our country with weakness. You have to show strength and you have to be strong."
Rioters ended up pushing past police and ransacking legislative offices, spraying graffiti on the walls and stealing property. In a video message posted to Twitter hours later, he called on the rioters to leave the Capitol, but also said, "We love you."
Since his election loss in November 2020, the president has constantly used the social media platform to baselessly claim the election was rigged or rampant with fraud. Twitter began labeling his tweets in the run-up to the election to say some of the information was disputed. However, they were not taken down.
Facebook suspended Trump's account indefinitely on Thursday, with Facebook CEO Mark Zuckerberg writing in a post that "the risks of allowing the President to continue to use our service during this period are simply too great. Therefore, we are extending the block we have placed on his Facebook and Instagram accounts indefinitely and for at least the next two weeks until the peaceful transition of power is complete."
Reddit on Friday removed the subreddit r/donaldtrump from its platform, with a spokesperson saying, "Reddit's site-wide policies prohibit content that promotes hate, or encourages, glorifies, incites, or calls for violence against groups of people or individuals."
Twitter has defended keeping Trump's account active in the past based on politicians and world leaders providing information in the public interest -- even if they go against Twitter policy for average users. But Twitter said Thursday they felt that was no longer the case with Trump.
"Our public interest framework exists to enable the public to hear from elected officials and world leaders directly," Twitter wrote. "It is built on a principle that the people have a right to hold power to account in the open."
The statement continued, "However, we made it clear going back years that these accounts are not above our rules entirely and cannot use Twitter to incite violence, among other things. We will continue to be transparent around our policies and their enforcement."
A number of Trump associates were banned from Twitter earlier in the day Friday. Michael Flynn, Trump's first national security adviser, whom the president pardoned late last year for lying to the FBI during the Russia investigation, was banned, as well as lawyer Sidney Powell, who briefly served on Trump's legal team following the election.
Trump has used Twitter as his main outlet for disseminating information for a decade. His posts during his presidency, sent from the same personal account he's used since March 2009, often generated headlines themselves.
Calls for Twitter to ban Trump, while increasing in the months since Election Day, are nothing new. Vice President-elect Kamala Harris repeatedly said while she was running for president that he should be banned.
She wrote a letter to CEO Jack Dorsey in October 2019, citing a handful of tweets she said broke the platform's policy. Twitter pointed to its public interest policy and said they did not plan to ban his account.
He had approximately 79.5 million followers on Twitter at the time of his removal -- the eighth-most followed account on the platform. Former President Barack Obama has the most followers at over 127 million, followed by Justin Bieber, Katy Perry, Rihanna, Cristiano Ronaldo, Taylor Swift and Lady Gaga.
ABC News' Ben Gittleson, Zohreen Shah, Matthew Fuhrman and Evan McMurry contributed to this report.