d'Arby began a presenting career while still a student of acting at RADA. In the early 1990s she presented on Children's BBC and then on SMart and had her own show 'Josie' on Channel 5. She has since presented a number of high profile programmes including the Bigger Breakfast (a spinoff from The Big Breakfast) and Top of the Pops. Recently she has been a presenter on BBC Young Musician of the Year, BBC Cardiff Singer of the World and BBC Choir of the Year
Josie won a Royal Television Society award for her work Presenting the BBC Current affairs programme 'Inside Out West' .
Josie is a fellow of the University of Wales.
d'Arby's first high-profile dramatic acting role was as series regular WPC Jodie Finn, in the BBC drama, Merseybeat . From February 2005, she starred as Peally Maghti, one of the presenters of the BBC's award winning spoof of 1980s science programming, Look Around You. d'Arby was one of the six cast members in Channel Four sketch series Spoons, and has recently made guest appearances in BBC Comedy series 'Miranda' and appears as herself in the Working Title movie 'Blackball'.
d'Arby has also appeared on the stage.
In Summer 2012 Josie was one of 8 core walkers who walked 200 miles from South to North Wales in aid of Wales Air Ambulance charity.
D'Arby was namechecked in the YouTube hit video by M.-J. Delany "Newport (Ymerodraeth State of Mind)" with the explanation: "Yes, it's strange, we didn't know either - Thank you Wikipedia." She appeared in the 2011 video for the song, along with several other Welsh celebrities, made for Comic Relief.
Continuing her diverse career in television and the arts, Josie now works as a writer director and her first play ' The Newport Monologues' about life in her hometown, opened to rave reviews from press and audience in September 2012.
In November 2011 she wrote and directed the off-beat New York Comedy ' A Magpie in the Mirror'.