Danniella Westbrook began her career as a child model and appeared in various advertising campaign. She also became the face of the high street store Tammy Girl. She then acted on stage and appeared in the music video of British rock band Queen’s song ‘The Invisible Man’ (1989). Thereafter, she was cast in the role of Sam Mitchell in BBC One's popular soap opera ‘EastEnders’ (earlier, she appeared on the show as an extra). This became her breakthrough role and she went on to portray her character from 1990 to 1993. She later returned to the show several times and played her character for short periods– 1995–1996, 1999–2000, 2009–2010 and 2016. In total, she acted in around 330 episodes of the TV series. After she quit ‘EastEnders’ in 1993, she picked up the role of Dawn Dillon in the comedy drama series ‘Frank Stubbs Promotes’. She acted in two series of the show (13 episodes) from 1993 to 1994.
In 2003, Danniella Westbrook participated as a contestant in the second series of ITV’s survival reality show ‘I'm a Celebrity...Get Me Out of Here!.’. However, she quit the show after just nine days. She then appeared as herself in TV series like ‘Bo' Selecta!’ (2003), ‘Most Haunted’ (2003), ‘I'm Famous and Frightened’ (2004) and ‘The Weakest Link’ (2006). Apart from these, Danniella Westbrook also presented the TV show ‘Cosmetic Surgery Live’ (2004) and ‘Derek Acorah's Ghost Towns’ (2005-2006, 19 episodes). In 2010, she participated in another reality show – this time in the fifth series of hit show ‘Dancing on Ice’. In the show, she was paired up with professional ice-skater Matthew Gonzalez and became one of the favourites to win. However, in the semi-finals, she lost to actor Gary Lucy and was eliminated from the show. She placed fourth in the show. During this time, she also appeared as herself in the spin-off show 'Dancing on Ice: Friday'.
Danniella Westbrook was then selected to play the recurring role of Trudy Ryan in the soap opera ‘Hollyoaks’. She played the character in 15 episodes of the show in 2013. She next played the roles of Michelle in director Terry Lee Coker’s drama film 'Essex Vendetta' and The Mother in director Liam Galvin’s thriller film 'Mob Handed'. Both these films released in 2016. The same year, she participated in the 17th series of the reality show ‘Celebrity Big Brother’ and reached the finals. She eventually finished 5th in the show. Since 2016, she has appeared as herself/guest in various television talk shows like ‘Good Morning Britain’, ‘Loose Women’, ‘Jeremy Vine’ and ‘Tonight LIVE with Mark Dolan’.