She is the daughter of actors Annette Crosbie and Michael Griffiths. Her only brother, Owen Griffiths, is a sound engineer at a post production sound facility in London. She trained at the Central School of Speech and Drama and has appeared in many plays as a result of this.
Griffiths has appeared in many television programmes, including Dr. Finlay, Inspector Wycliffe and Drop the Dead Donkey. However, it is for her role of Janet, in The Smoking Room, that she is probably best known. In Autumn 2007 she co-starred with Deborah Findlay in the BBC1 costume drama series Cranford playing Miss Caroline Tomkinson. In January 2011 she appeared as a frightened passenger in the BBC1 comedy series Come Fly With Me, which is written by Matt Lucas and David Walliams. In February 2011 she appeared as "Pauline" in the ITV Show Benidorm and through March-April appeared in the Jeremy Dyson play adaption of Roald Dahl's Twisted Tales. In March 2012 she appeared as Yvonne in the BBC3 series, Being Human.
TV work includes:
- Doctor Finlay "Old Flames" (1995) as Pamela
- The Smoking Room (2004-2006) as Janet
- Cranford (2007) as Caroline Tomkinson
- Benidorm (2011) as Pauline
- Being Human "Hold the Front Page" (2012) as Yvonne