Tucker Carlson’s popular show “Tucker Carlson Tonight” has held the weeknight 8 p.m. slot since 2017, when it replaced Bill O’Reilly’s show after he was fired from the network.

Often pushing conspiracy theories and racist narratives, “Tucker Carlson Tonight” became the most-watched show in prime-time cable news, averaging 3.25 million viewers in the first quarter of this year.

A Fox spokeswoman said on Monday that the show would be replaced with a new program called “Fox News Tonight.”

The Fox News host Harris Faulkner said Monday while on air that, starting Monday evening, the interim show would fill the 8 p.m. hour “with rotating Fox News personalities until a new host is named.”

Mr. Carlson’s last show was on Friday. In it, he appeared not to not know it was his finale. He ate a sausage and pineapple pizza with a delivery man who had thwarted a man running from police and told viewers: “We’ll be back on Monday. In the meantime, have the best weekend with the ones that you love.”