Murnaghan worked as a trainee reporter on local newspapers before joining Channel 4 as a researcher and later a reporter for The Business Programme. Murnaghan presented the European Business Channel in Switzerland before being recalled by ITN to present the World News on The Channel 4 Daily between 1991 and 1992 after the departure of original anchor Carol Barnes. Murnaghan presented programmes on ITV such as the ITV Lunchtime News and News at Ten. In 1997, as an ITN news presenter, Murnaghan broke the news of the death of Diana, Princess of Wales to viewers on ITV. He later presented the ITV Evening News and the ITV Nightly News when ITV relaunched their news output in 1999. He also worked on ITV's general election coverage in 2001. From September 2002 to December 2007 Murnaghan was a main presenter of BBC Breakfast, replacing Jeremy Bowen. He presented the show alongside Sophie Raworth, Natasha Kaplinsky, Kate Silverton, Sian Williams and Susanna Reid. He was also a regular stand-in on the BBC Six O'Clock News and BBC Ten O'Clock News and co-presented the BBC News at Six on Fridays from September 2003 to summer 2007 alongside Sian Williams. His presenting style was lampooned in the impersonation sketch show Dead Ringers by Jon Culshaw, his widely spaced legs on the presenting couch mocked with the phrase 'I'm Dermot Murnaghan, watch my crotch follow you round the room'. Whilst at the BBC, he presented BBC One's Treasure Hunt, a revival of an earlier format on Channel 4 Television. He co-presented BBC Breakfast from Monday to Thursday as well as regularly fronting national BBC news bulletins until December 2007. In October 2007, it was announced that Murnaghan would be leaving the BBC for Sky News. Murnaghan became the second news presenter to depart the corporation in the same month – Natasha Kaplinsky also left to join Five News, produced by Sky. His last time presenting Breakfast was 20 December 2007. Murnaghan presented the BBC Two daytime show Eggheads from 2003 until 2014, as well as its short-lived spin-off series Are You an Egghead? in 2008 and 2009. After his move to Sky News he shared this role with Jeremy Vine, who subsequently became the sole presenter in series 16. He also presented the BBC revival of Channel 4's 1980s hit Treasure Hunt alongside Suzi Perry. Murnaghan has guest presented reports for different travel shows including ITV's Wish You Were Here...? and BBC One's rival programme Holiday. He has made cameos as a newsreader in the 2004 film Wimbledon, Absolute Power and Midnight Man. From January 2011 until December 2016, Murnaghan presented his own show entitled Murnaghan on Sky News that aired on Sunday mornings from 10 am until 12 noon. From September 2016, he has presented Sky News Tonight from Monday to Thursday. For the 2019 United Kingdom general election Murnaghan hosted Sky News' overnight coverage, entitled The Brexit Election.
On 19 January 2015, Murnaghan was criticised for his hostile attitude towards Shadow Business Secretary Chuka Umunna during an interview where Murnaghan asked Umunna if he agreed with the statement sent by the Communities Secretary to the Muslim community earlier in the day. Umunna acknowledged that he had not read it, though Murnaghan nonetheless continued to press the Shadow Business Secretary, resulting in an abrupt end to the interview when Murnaghan cut-off Umunna mid-speech by saying "so you are not going to speak until you get the party line right?" Viewers complained about the lack of journalistic standards, insinuating remarks and poor attitude exhibited by Murnaghan during the interview.
On 8 February 2015, Murnaghan announced the Estonian president, Toomas Hendrik Ilves, as Toomas Hendrik and proceeded to call him "President Hendrik". President Ilves removed his microphone and left, saying "Tell him to shut up, he can't even get my name right."
Personal life
In August 1989 Murnaghan married Maria Keegan in Camden; they have four children. They live together in North London. Murnaghan is an Arsenal fan. In 2006, Murnaghan became president of the Television and Radio Industries Club and presented the TRIC Awards 2007. On 9 March 2017, Murnaghan was involved in a hit and run accident. He was cycling through Kentish Town, northwest London, to his work at Sky News, while wearing a hi-vis jacket and helmet when the accident took place. Speaking to Sky News, Murnaghan said the driver of the car which hit him had been using a mobile phone when the incident occurred. The accident forced Murnaghan to be off air from his Sky News show and resulted in his having large bruise marks on the left hand side of his face. The presenter thanked a 'good samaritan' who saw what had happened and told him that the car had sped off.
