"We finally agree on something Rosie," Trump tweeted, along with a link to a December 2016 O'Donnell tweet that read: "FIRE COMEY."
"@realDonaldTrump - u don't even realize the kind of trouble u r in - comeys people believe in him - for real - they have the proof - u r a sadistic man #USA" O'Donnell replied in a tweet Thursday.
But this is only the latest development -- and likely not the last -- in Trump and O'Donnell's decades-long, highly public feud.
How did it start? Here is a timeline, documenting highlights from 2006-2017:
When Trump decided not to fire Miss USA Tara Conner
after revelations of drug use, underage drinking and sexual activities, the co-owner of the Miss USA pageant raised some eyebrows.
"I've always been a believer in second chances. Tara is a good person. Tara has tried hard. Tara is going to be given a second chance," Trump said on December 19. Conner was allowed to keep her crown but had to go to rehab.
The next day O'Donnell, who was a co-host of "The View" at the time, criticized his decision, saying that she doesn't "enjoy" Trump and said he went bankrupt -- a claim Trump continues to deny, most recently at Thursday's GOP debate.
She added that Trump is "not a self-made man" but a "snake-oil salesman on Little House On The Prairie," and she proceeded to slam his multiple marriages: "[He] left the first wife -- had an affair. [He] had kids both times, but he's the moral compass for 20-year-olds in America. Donald, sit and spin, my friend."
Following those comments, Trump fired back at the comedian and told People Magazine
that O'Donnell is "a real loser" and "a woman out of control."
"You can't make false statements. Rosie will rue the words she said," referencing her claims that he went bankrupt. "I'll most likely sue her for making those false statements -- and it'll be fun. Rosie's a loser. A real loser. I look forward to taking lots of money from my nice fat little Rosie."
Only eight months after joining "The View," O'Donnell left the show after a heated spat with fellow co-host Elisabeth Hasselbeck over the war in Iraq.
Trump, who insulted both hosts, surprisingly took O'Donnell's side because he was also against the war.
"On this one I think Rosie should win, but Rosie is not much herself. I think anybody that's against the war in Iraq is the winner of the fight, because to justify the war in Iraq -- only an imbecile could do that," he told "Extra,"
calling Hasselbeck "not a very smart person, she's one of the dumber people in television."
But this was not the beginning of a change of heart.
After O'Donnell announced
her engagement to then-girlfriend Michelle Rounds in December, Trump took to Twitter to share his thoughts, tweeting, "I feel sorry for Rosie 's new partner in love whose parents are devastated at the thought of their daughter being with @Rosie--a true loser."
O'Donnell responded promptly by calling him "an a--."
Trump also called O'Donnell's new show on Oprah Winfrey's network OWN "a complete and total disaster."
Trump tweeted a video simultaneously bashing O'Donnell's show "Rosie" and MSNBC's Lawrence O'Donnell, who has also been the subject of Trump social media insults multiple times.
"Same last name, same bad ratings- @lawrence and @rosie," Trump tweeted.
"It's really amazing. When I don't like somebody their shows do really badly," he said, adding that it "upsets" him that O'Donnell's show is a "disaster" because he loves Oprah and wants her to be successful.
While attacking Cher for slamming then-Republican presidential candidate Mitt Romney, Trump snuck in an insult directed at his favorite nemesis, tweeting ".@Cher attacked @MittRomney. She is an average talent who is out of touch with reality. Like @Rosie O'Donnell, a total loser!"
When O'Donnell suffered a heart attack
, she got well wishes from none other than The Donald himself.
"Rosie, get better fast. I'm starting to miss you!" he tweeted.
O'Donnell acknowledged that his well wishes took her by surprise and tweeted, "well thank u donald - i must admit ur post was a bit of a shock ... r u trying to kill me ?"
After undergoing a weight-loss surgery in 2013, O'Donnell revealed
her 50-pound weight loss.
"I did what many women do, and I did not take care of myself," she said during a speech at an American Heart Association luncheon in Detroit in February. "And that's why I'm here, to try to get women to know you're worth it, take care of yourself and know the symptoms."
Trump tweeted the following month, "Rosie O'Donnell just said she felt 'shame' at being fat-not politically correct! She killed Star Jones for weight loss surgery, just had it!"
O'Donnell responded with "Donald — go away."
On July 10, ABC officially announced
that O'Donnell would be returning to "The View" as a co-host in September.
And while her former co-host Hasselbeck was not pleased
with the news, Trump welcomed it, calling it
a "good move on ABC's part."
But his reaction didn't end there.
Trump added that O'Donnell's addition to the show will "have a short term positive effect. The show has really missed not having Barbara [Walters] on it."
He then later tweeted: "Rosie is back on the View which tells you how desperate they must be. It is the standard short term fix and long term disaster."
He followed up an hour later with, "Rosie is crude, rude, obnoxious and dumb - other than that I like her very much!"
Upon making her comeback as a co-host of "The View," O'Donnell discussed
her emotional journey following her weight loss and told "People" that the criticism she got from Trump was the worst bullying she had been through.
"Probably the Trump stuff was the most bullying I ever experienced in my life, including as a child," O'Donnell said. "It was national, and it was sanctioned societally. Whether I deserved it is up to your own interpretation."
Trump responded to her comments by tweeting, "Rosie—No offense, and good luck on the new show, but remember, you started it!"
After joining the "The View" in September, 2014, O'Donnell left the talk show for the second time.
"The truth is, I had a heart attack two years ago and stress is very bad for a heart-attack survivor," the comedian said in a video for her fans. "I'm minimizing my stress by leaving 'The View.' The stress I'm having at home is not easily as remediable ... There's lots of stuff going on at home."
Asked about the struggling show, Trump said
, "Well, it's very sad what's happened to 'The View' and I predicted that with Rosie O'Donnell it would fail. I guess the prediction is correct, but, I mean she's a total trainwreck, so let's see what happens and I hope it works out well. ... I like the show a lot, but let's face it, Rosie is a loser."
The Trump-O'Donnell feud first made its way into the 2016 campaign spotlight during the first Republican presidential primary debate.
When Republican frontrunner Donald Trump was asked
by Fox News host and debate moderator Megyn Kelly about his use of language like "fat pigs," "dogs," "slobs" and "disgusting animals" to describe some women, The Donald didn't miss a beat.
"Only Rosie O'Donnell," he interjected, generating gasps, applause and laughter from the crowd.
O'Donnell, who has been an arch-nemesis of the billionaire mogul for about a decade, responded to Trump's dig by tweeting, "try explaining that 2 ur kids."
The morning after the debate, Trump appeared on "Fox and Friends" and noted that the crowd was pleased with his comments about the comedian and former host of "The View."
"And then [Megyn Kelly] hit me with a very, very hard question," Trump said. "That was when I came up with the Rosie O'Donnell statement, which really got a tremendous applause. That was the biggest applause in the evening actually, so it was sort of interesting."
Trump once again attacked his arch nemesis live at a national political event — his first presidential debate where he faced off against Democratic presidential candidate Hillary Clinton on September 26.
Trump's reference to O'Donnell came up after Clinton accused Trump of sexism during the debate, saying, "This is a man who has called women pigs, slobs and dogs.
"Hillary is hitting me with tremendous commercials. Some of it I said in entertainment, some of it said to somebody who has been very vicious to me, Rosie O'Donnell," Trump responded. "I said very tough things to her and I think everybody would agree she deserves it and nobody feels sorry for her."
O'Donnell slammed Trump on Twitter Monday night after he resurrected their longtime feud during the first presidential debate, saying that comments he made about the comedian and TV host in the past — including calling her a "pig" — were justified.
Declaring her support for Clinton, O'Donnell tweeted, "HE WILL NEVER BE PRESIDENT" and then later called on people to "shame the Donald."
November 2016 and beyond
O'Donnell was wrong.
When Trump defeated Clinton in November, the actress was beside herself, tweeting, "god help us all."
"i am not scared - i am sad - for all of us - for humanity - @TBoneisT360," she added in response to a Twitter user who tweeted, "as upset as many of us are imagine how scared to death @Rosie must be this morning.... #ElectionHangover."
Since then, O'Donnell has been one of the most outspoken celebrity critics of the President on social media and even traveled all the way to the White House
in February to protest ahead of Trump's first joint address to Congress.
But until Thursday, Trump had been publicly silent on O'Donnell since getting elected.