But Kelly isn't there to be a conservative megaphone.
"I'm not going to be the female Bill" O'Reilly, Kelly said, ahead of the premiere of "The Kelly File." "I'm a news anchor, I'm not an ideologue. I don't want to be an opinion anchor."
Kelly has shown a willingness to challenge people of all political stripes, famously calling out Karl Rove on election night when he tried to get the network to take back its call of Ohio for President Barack Obama.
"People know that they are going to get the real me when I go out there," she said. "If somebody comes on and is a moron, I'm going to call them out.
Her first guest Monday was controversial firebrand, Texas Sen. Ted Cruz, and she didn't hold back.
"What's it like to be the most hated man in America?" she asked, not waiting to let Cruz get comfortable in his chair.
But the hard-charging Kelly ended on a softer note, introducing viewers to her 9-week-old son, Thatcher.