Born in Sussex, she was raised in London. She first joined her local BBC Radio station as a junior music correspondent, but knew little about the local indie band.

After studying politics at Queen Mary, University of London, Hill worked at the Democratic National Headquarters in Washington DC before joining the BBC on a full-time basis at the end of 1991.

After completing the BBC journalism training programme, Hill joined BBC Radio Five Live at the station's launch, remaining there as a producer for 18 months. She moved into television following completion of the BBC Regional News Trainee Scheme. She went on to join BBC Radio Berkshire and South Today as a presenter, before moving later to national news.

When BBC News launched its new 24 hour channel in November 1997, Hill joined, and was originally an overnight presenter, also appearing on the channel's international counterpart BBC World News during the simulcast between the two channels. During her time with BBC News, she has presented coverage of a wide range of stories and events, including a week of special programmes from Washington DC in the aftermath of the terrorist attacks of 11 September 2001. She also went on to present live coverage on BBC News and BBC World News of the first anniversary commemorations at Ground Zero in New York.

She presented numerous special programmes on BBC One and BBC Two during the war in Iraq, and in December 2003, on the day US forces captured Saddam Hussein, she broadcast for nearly eight hours continuously on both terrestrial channels, BBC News, and BBC World News.

Hill led the local reporting in Portugal in 2007, for the BBC's coverage of the disappearance of Madeleine McCann. Flying to Portugal the day the news broke, she spent much of May there, and conducted the BBC’s first interview with Kate and Gerry McCann. She returned to the Algarve for all the major developments in the story, and made a half hour documentary about the case at the end of that year.

Since April 2006, she has presented alongside Matthew Amroliwala between 1100 and 1400, Monday to Friday. Previously, she presented with Chris Eakin from 1900-2200 on Monday to Thursday evenings. Hill also presents news bulletins on BBC One, and in the past has made occasional appearances presenting BBC Breakfast.

On Monday 16th August 2010, she began a week sitting in for Jeremy Vine on BBC Radio 2's music and news programme.

In her spare time, Hill is a keen supporter of the arts, and enjoys food and wine - as well as swimming, going to the gym, and The Archers.

She lives in North London with her partner Sara, a camera operator.She previously dated TV presenter Chris Hollins.