From Colbert's alter-ego bursting into tears to Kimmel crony Guillermo's own "The Guillerm O'Factor," see late-night's biggest moments eviscerating the former Fox News host.
"The Late Show With Stephen Colbert"
Colbert and his alter-ego sent O'Reilly off on Wednesday night's airing of "The Late Show With Stephen Colbert" with a bang.
"It's like looking at your front yard and the big oak tree is just gone," Colbert said about the departure of O'Reilly from Fox News. "I'm sure the oak tree said some disturbing things about young black men with their rap music and their neck tattoos, but damn it the tree had been there forever. And your grandpa liked to just sit there and stare at it, and then the tree would sell your grandpa gold coins and self-lubricating catheters."
Colbert's alter-ego later took the spotlight with his own statement. "Hello, nation, and shame on you," he said. "You failed him. You failed Bill O'Reilly. All he ever did was have your back, and if you're a woman, you know, have a go at the front too."
"And what?" he asked. "Suddenly sexual harassment's a crime? Well, that's the country we live in now, Obama's Trump's America."
Colbert's alter-ego later burst into tears and closed by saying, "Stay strong, Papa Bear."
"The Late Late Show With James Corden"
Corden bid O'Reilly farewell by poking fun at the former Fox host's collection of books.
"Fox News had no choice," Corden said about O'Reilly's departure. "They have a very strict '28 strikes and you're out' policy."
"When a woman from Fox News called O'Reilly to tell him that he was fired, she said, 'Look Bill, thank you for everything you've done, but the time has come to ... wait, Bill, are you masturbating?" Corden said.
Taking a swipe at Donald Trump, Corden said, "This is a lesson for all of us. If you behave like an animal who sexually harasses women, you can't host a talk show. You can be President, but you can't host a talk show."
Corden, addressing the pundit's publishing history later said, "In addition to being cable's top-rated host, O'Reilly's written a number of best-selling books, including 'Killing Lincoln,' 'Killing Reagan,' and 'Killing Kennedy.'"
"I really look forward to his next book," Corden said, "'Killing Time at Home.'"
"The Tonight Show With Jimmy Fallon"
Fallon took his own shot at O'Reilly and said, "Today, Fox News announced that Bill O'Reilly has been fired after his sexual harassment scandal."
"Experts say that it's not likely that any self-respecting network would ever hire him," Fallon said and took a jab at CNN.
"Then CNN said, 'Welcome aboard,'" he joked.
See what the late-night host said about O'Reilly's visit with the Pope in the hilarious video above.
"Jimmy Kimmel Live!"
Kimmel and sidekick Guillermo took on O'Reilly's departure on "Jimmy Kimmel Live!"
"Bill O'Reilly was fired today," Kimmel said on Wednesday night, detailing the sexual harassment allegations and the news anchor's vacation visit to the Pope.
"Fox News decided to extend Bill's vacation to forever," Kimmel joked as he introduced O'Reilly's replacement -- Guillermo.
See the spoof ad for the "new" show above.