US President-elect Donald Trump said he was naming former congressman and Fox host Sean Duffy as his nominee for transportation secretary, as he continues to roll out picks for his Cabinet.

Former Wisconsin representative Mr Duffy was one of Mr Trump’s most visible defenders on cable news — a prime concern for the media-focused president-elect.

Mr Duffy served in the House of Representatives for nearly nine years, was a member of the financial services committee and chairman of the subcommittee on insurance and housing. He left Congress in 2019, and is co-host of The Bottom Line on Fox Business.

In his announcement, Mr Trump said that Mr Duffy was married to a Fox News host, calling him “the husband of a wonderful woman, Rachel Campos-Duffy, a STAR on Fox News”.

Donald Trump said Sean Duffy would use his experience and relationships built over years in Congress ‘to maintain and rebuild our nation’s infrastructure’ (Allison Robbert/Pool via AP)

A spokesperson for Fox News Media wished Mr Duffy “the best of luck in his return to Washington” and said he left the company on Monday.

Mr Duffy is so far the second Fox-affiliated television host that Mr Trump has named to his Cabinet.

Mr Trump last week announced his choice of Fox News host Pete Hegseth to serve as his defence secretary.

Mr Trump said Mr Duffy would use his experience and relationships built over the years in Congress “to maintain and rebuild our nation’s infrastructure, and fulfil our mission of ushering in the golden age of travel, focusing on safety, efficiency, and innovation. Importantly, he will greatly elevate the travel experience for all Americans!”

Donald Trump announced his choice of Fox News host Pete Hegseth to serve as his defence secretary last week (Evan Vucci/AP)

Mr Duffy ruled out a run for Wisconsin governor in 2022 despite pleas from Mr Trump to make a bid, saying he needed to care for his nine children, including his youngest child who had a heart condition.

He is a former lumberjack athlete and frequent Fox News contributor. He was featured on MTV’s The Real World: Boston in 1997. He met his wife on the set of MTV’s Road Rules: All Stars in 1998.

A reality television background before politics is not unusual in Mr Trump’s world. The former president launched his political career after his hit reality show The Apprentice.

Mr Duffy, after his time on reality television, worked as a special prosecutor and Ashland County district attorney. He won election to Congress in 2010.