O'Reilly's exit came nine months after his former boss, Fox News CEO Roger Ailes, was ousted after allegations of sexual harassment.
Following the Times story, 21st Century Fox said it had asked the same law firm that investigated Ailes to look into O'Reilly's behavior. 21st Century Fox leaders Rupert Murdoch and his sons Lachlan and James said in a memo to Fox staff that their decision to ax O'Reilly came after an "extensive review" into the charges.
O'Reilly, denied a chance to say goodbye to his Fox viewers, did so via a statement.
"It is tremendously disheartening that we part ways due to completely unfounded claims," he said. "But that is the unfortunate reality that many of us in the public eye must live with today. I will always look back on my time at Fox with great pride in the unprecedented success we achieved and with my deepest gratitude to all my dedicated viewers."
Fox said conservative pundit Tucker Carlson would move into O'Reilly's time slot — the second time in three months he has replaced an exiting prime-time personality. Carlson had taken over for Megyn Kelly in January when she announced she was moving to NBC News.
O'Reilly, 67, had ruled the "no spin zone" on television with a quick smile and an even quicker temper. He pushed a populist, conservative-leaning point of view born from growing up on Long Island and was quick to shout down those who disagreed with him. Fans loved his willingness to talk back to power or point out hypocrisy among liberal politicians or media members.
His show generated $178 million in advertising revenue in 2015, according to Kantar Media.
O'Reilly's pugnacious personality wasn't just an off-screen affectation; one of the settlements went to a woman who complained about being shouted at in the newsroom. One harassment case, from a former producer who said O'Reilly called her and described sexual fantasies and appeared to be masturbating, dated back more than a decade and was widely reported then. While O'Reilly survived then, the accumulation of cases outlined in the Times damaged him much more extensively.