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The move comes after a tumultuous year for Kelly - from clashing publicly with President-elect Donald Trump and his supporters to sharing her story of allegedly being sexually harassed by former Chairman and CEO Roger Ailes, who was ousted from the network in July.
She signed on with NBC for an unspecified multiyear contract, the amount of which hasn't been made public. Kelly was reportedly making $10 million to $12 million a year at Fox.
In her memoir "Settle for More," Kelly describes how she landed her first job as a lawyer fresh out of law school in 1995, and offers advice for anyone applying for a new job in any field.
"I did something all job applicants should do - I asked for the job," she wrote. "I told them that if they extended an offer, I would accept it on the spot, that I had done the research and investigation, and this was where I wanted to be."
After that meeting with the law firm, they offered her a job paying $85,000 a year, a welcome sum to a recent grad with $100,000 in school loan debt.
"Don't underestimate the power this message can have on a potential employer," Kelly wrote. "Everyone likes to be flattered. Of course it works better if it's true."
"Settle for More" has been on the New York Times Best Sellers list since it debuted November 15. Kelly's show airs weeknights on Fox News at 9 p.m. ET, and her last episode will air Friday, January 6.