Megyn Kelly Being Replaced by Tucker Carlson at Fox

Tucker Carlson, the veteran cable television host and conservative writer, will succeed Megyn Kelly in the coveted 9 p.m. slot on Fox News, solidifying the network’s right-wing identity in prime time as it prepares to cover the administration of President-elect Donald J. Trump.

The move, announced on Thursday, comes just weeks after Mr. Carlson, a former co-host of CNN’s “Crossfire” and founder of the Daily Caller, the right-leaning news and opinion site, took over Fox News’s 7 p.m. hour. In that role, he has scored high ratings while generating provocative exchanges with guests that earned traction — and some criticism — online.

Mr. Carlson’s elevation means that Fox News, for the first time in its two-decade history, will have an all-male anchor lineup from 8 to 11 on weeknights, after a year in which the network faced serious questions about its treatment of female employees and in which its chairman, Roger Ailes, was ousted in a sexual harassment scandal.

It also marks a swift conclusion to an anchor sweepstakes that only emerged on Tuesday, when Ms. Kelly, the network’s No. 2 anchor behind Bill O’Reilly, announced that she would be leaving Fox for NBC News, where she planned to host a daytime news show and Sunday newsmagazine. Even senior officials in Fox’s newsroom were startled on Thursday when news of Mr. Carlson’s appointment emerged on The Drudge Report.

Martha MacCallum, co-anchor of Fox News’s morning news show “America’s Newsroom,” is to succeed Mr. Carlson at 7 p.m. Her program, “The First 100 Days,” which begins Jan. 16, will air for the first 100 days of Mr. Trump’s administration, with its future to be determined later, network officials said.

Fox’s announcement was the start of a day of musical chairs in the cable-news industry. Greta Van Susteren, the Fox News anchor whose departure last fall opened the door for Mr. Carlson’s return to the nighttime lineup, is joining MSNBC for a daily 6 p.m. show.