Box's early career was spent in regional Australia working at stations 2MC/ROXFM Port Macquarie, 3TR Traralgon and 3GG Warragul.
In 2000, Box co-hosted a late-night show on TTFM Melbourne and within months, was picked up by the Triple M network to co-host a national night show based on relationships. When the show came to an end, she moved to the breakfast timeslot to produce Amanda Keller, Mikey Robins and Peter Berner.
In 2003, Box joined The Shebang on Triple M and stayed with the station until 2008.
Box is known on television for her "standout" performance on Dancing with the Stars on the Seven Network in 2007 and regular guest appearances on Sunrise and Thank God You're Here.
In January 2009, Box joined Sunrise as weather presenter where she replaced David Brown and stayed in this position until December 2009. In January 2010, she was appointed as Entertainment Editor on Sunrise where she interviewed celebrities and presented entertainment segments. Grant Denyer returned to Sunrise as weather presenter.
In November 2010, it was revealed that Box was hired as a co-host with Jules Lund on Fifi and Jules across the Today Network leaving Friday's show open for Hamish and Andy to do their show. The show started in February 2011.
In November 2013, Box announced that she was going to co-host Fifi & Dave with Dave Thornton on Fox FM in 2014 replacing Jo Stanley and Matt Tilley. In 2016, Brendan Fevola joined the show and it was renamed Fifi, Dave and Fev. In January 2017, anchor Byron Cooke was added to the title of the show and it was renamed Fifi, Dave, Fev & Byron.
Box joined the cast of Neighbours in July 2016 as Brooke Butler. She made her debut on the show on 28 September 2016 and left at late November, her character returned in April 2017.
Box was raised in the outer eastern suburbs of Melbourne, Victoria, Australia. She attended Tintern Girls Grammar School in Ringwood and in her final year was appointed school captain. Box often returns to Tintern to speak with current students. Her brother is Augie March's keyboardist Kiernan Box.
On 19 November 2012, Box announced on live radio via her radio show "Fifi and Jules" that she was pregnant. On 17 December, it was reported that Grant Kenny was the father. On 5 April 2013, Box gave birth to a baby girl.