Maitlis was born to British parents in Canada but raised in Sheffield, Yorkshire, where she was educated at the King Edward VII School. Her first occupation was as a trainee hairdresser. A Cambridge University graduate who studied at Queens' College, she speaks fluent Spanish, Italian and French, as well as some Mandarin. Prior to working in news, she was a documentary maker in Cambodia and China. She worked for the NBC network and was based in Hong Kong.
Previously, she spent six years with NBC Asia, initially as a business reporter creating documentaries, and then as a presenter in Hong Kong covering the collapse of the tiger economies in 1997. She also covered the transfer of sovereignty over Hong Kong with Jon Snow for Channel 4. She then moved to Sky News in the UK as a business correspondent, and then to BBC London News when the programme was relaunched in 2001.
During 2005, Maitlis appeared as the question-master on the game show The National Lottery: Come And Have A Go. She has also presented BBC Breakfast, and from May 2006 until July 2007, she presented STORYFix on BBC News, a light-hearted look at the week's news set to up-beat music.
In July 2007, Maitlis was appointed as a contributing editor to The Spectator magazine, an unpaid post. This had been approved by her immediate boss, the head of BBC Television News Peter Horrocks, but the decision was subsequently overturned by his superior, the BBC News director Helen Boaden.
In 2012, Maitlis presented the US 2012 programme on BBC One and the BBC News Channel alongside David Dimbleby, when US President Barack Obama and Mitt Romney were fighting to the presidency for the US. In 2016, she began presenting a news discussion programme called The World This Week on BBC Two late afternoon on Saturdays.
Maitlis is one of the main presenters of Newsnight on BBC Two, with Evan Davis and Kirsty Wark. She also presents relief shifts on the BBC News channel, including the BBC News at Five, and may occasionally present the BBC News at One which is also broadcast on BBC One. Maitlis was a regular presenter on BBC News during 2006, joining as part of a new line-up in April to present alongside Ben Brown from 7 pm to 10 pm during the week, but was replaced by Joanna Gosling when she went on maternity leave. On Maitlis' return, she began presenting Mondays 2 pm–5 pm alongside Jon Sopel until 2013, and currently Simon McCoy on Mondays.
From a Jewish family, Emily Maitlis is the daughter of Professor Peter Maitlis, FRS, Emeritus Professor of Inorganic Chemistry at the University of Sheffield, and Marion Maitlis. She is married to Mark Gwynne, an investment manager, whom she has referred to as "my Catholic boy". They have two children.
During 2002, it was reported that Maitlis had been stalked for six years by a former university friend, Edward Vines. The former student, 32, pursued Maitlis with correspondence, and would appear at her place of work. He admitted harassing Maitlis and was sentenced to four months' imprisonment. In September 2016 the same man was sentenced to three years' imprisonment for breach of a restraining order in respect of Maitlis.
In March 2007, David Decoteau, a 45-year-old convicted rapist, was sentenced to four life sentences whilst on probation, following another assault that had remained unsolved since 1996. During the trial, it was revealed that Decoteau had an "unhealthy fixation" with Maitlis, and that he kept photographs of Maitlis on the wall of his probation hostel room and had written to her from prison.