Tucker Carlson has moved seamlessly into Megyn Kelly's time slot at Fox News Channel, and has reportedly doubled the ratings of her 9pm segment.

Tucker Carlson Tonight has performed with a 95 per cent increase in the demographic of 25 to 50 year-old viewers, compared to the same time period last year when The Kelly File was on air.

Measuring the same time frame from January 11 to 22, Carlson has garnered an average of 775,000 viewers, which nearly doubles Kelly's 398,000, according to The Hill.

Measuring the same time frame from January 11 to 22, Carlson has garnered an average of 775,000 viewers, which nearly doubles Kelly's 398,000

Carlson averaged just under 3 million viewers for his first week of shows in Fox's prime-time lineup, or 10 per cent more than the 2.72 million viewers that Kelly averaged all of last year, the Nielsen company said.

Kelly announced on January 3 that she was leaving Fox News Channel for a new job at NBC News, where she will host a daytime hour

Fox's numbers are strong in general as many of its viewers eagerly await the start of the Trump administration.

Carlson's lead-in, Bill O'Reilly, averaged 3.5 million last week, or 7 per cent more than what he averaged last year. Sean Hannity, Fox's other prime-time personality, was up 16 per cent last week in the same measurement, Nielsen said.

Kelly announced on January 3 that she was leaving Fox News Channel for a new job at NBC News, where she will host a daytime hour that hasn't been defined yet, a once-weekly news magazine and participate in political coverage. Her start date at NBC hasn't been determined.

Carlson, who has hosted shows on CNN, MSNBC and PBS, earned his shot at Fox's prime-time lineup by doing well as a replacement for Greta Van Susteren earlier in the evening on Fox. Van Susteren has now taken a job at MSNBC.

Carlson averaged just under 3 million viewers for his first week of shows in Fox's prime-time lineup, or 10 per cent more than the 2.72 million viewers that Kelly averaged all of last year

Football dominated television last week, with the Pittsburgh Steelers' NFL playoff win in Kansas City seen by 37.1 million viewers and Clemson's late victory over Alabama for the NCAA championship reaching 24.4 million.

CBS won the week in prime time, averaging 10.3 million viewers. NBC had 9.1 million, Fox had 7.6 million, ABC had 4.7 million, Univision had 1.9 million, Telemundo had 1.6 million, ION Television had 1.3 million and the CW had 900,000.

With college football's premier game, ESPN led the cable networks with a prime-time average of 3.97 million. Fox News Channel had 2.48 million, USA had 1.62 million, HGTV had 1.6 million and TBS had 1.38 million.

NBC's Nightly News topped the evening newscasts with an average of 9.6 million viewers. ABC's World News Tonight was second with 9.2 million and the CBS Evening News had 7.6 million viewers.