The FOX News Channel host and Colbert, who has essentially based his comic character every evening on Comedy Central on him, will trade appearances on each other's programs Jan. 18.
"I'm really looking forward to speaking to a man who owes his entire career to me," O'Reilly said.
On "The Colbert Report," Colbert portrays a self-involved talk-show host who has tried to bring "truthiness" to the world. His character owes an obvious debt to O'Reilly, who holds court in the "no-spin zone" each evening.
On "The O'Reilly Factor," O'Reilly portrays a ... um, he hosts the top-rated program in cable news.
"I look forward to the evening," Colbert said. "It is an honor to speak face-to-face with a broadcasting legend, and I feel the same way about Mr. O'Reilly."
FOX News Channel is owned by News Corp., which is the parent company of FOXNews.com.