Griffiths was raised in Dolwyddelan, North Wales He set up his own theatre company aged 13 years old called Cwmni Ieuenctid Dolwyddelan. The company became successful and toured Wales competing in local theatre festivals. He was educated at Dolwyddelan school and later at Ysgol Dyffryn Conwy Secondary school in Llanrwst, North Wales. Griffiths took a three-year Media Course at the Y Coleg Normal, University of Wales, Bangor and after graduating in 1994, worked for numerous television companies as a Production Assistant, and later as an Assistant Producer and Director.

Griffiths won the Drama Medal at the National Urdd Gobaith Cymru Eisteddfod for the first time at the Preseli Eisteddfod in 1995 for a short play entitled O Gysgod y Cyll (From the Shadows) . He repeated his success in 1996 at the Bro Maelor Eisteddfod in Wrexham with another short play called B’echdan? (Sandwich?) later adapted and televised on the S4C Digital as B'echdan W??[1] (Egg Sandwich?). In 1997 he won again at the Islwyn Eisteddfod in Crosskeys with the play Ai am fod haul yn Machlud? (Is it because the sun is setting?) which was also later adapted and televised on S4C Digital under the new name of Traeth Coch (Red Beach) starring Mali Harries. In 2000, at the Bro Conwy Eisteddfod held in Llandudno he was invited to adjudicate the competition and at the 2008 Eisteddfod, again held in Llandudno presented the Ceremony live on S4C. In 2010, Griffiths will be adjudicating the Drama Medal for the second time at the Ceredigion Urdd Eisteddfod.

Griffiths started his career in television production as a part of his work experience in his second year at Y Coleg Normal, University of Wales, Bangor, when he worked as a Runner on S4C's adaptation of the Saunders Lewis play Brad (Treason). After completing his Degree, he joined Eryri Films and worked on several drama series such as Tydi Coleg yn Gret (Isn’t College Great) and I Dir Drygioni (Into the Evil Earth) and numerous light-entertainment series for S4C. In 1995, he spent a year working as an Assistant Film Editor on S4C's eight-part family drama series Lleifior. He joined Cwmni Da as a Researcher and later Assistant Producer in 1997, and contributed to BAFTA Cymru Award Winning series such as Y Sioe Gelf (The Arts Show), Popeth yn Gymraeg (Everything in Welsh) and Jones Jones Jones. In 2006, he filmed and directed a 30 minute documentary in the series Love Hurts for ITV1 Wales. He has also worked on co-productions for TG4, S4C and ITV1 Wales with Midas Productions, Dublin such as Frongoch - Coláiste na Réabhlóide [2] (Frongoch — University of Revolution) and Celtic Monsters which won an Award at the Celtic Film and Television Festival in 2006. In June 2007, he left North Wales and re-located to London. Griffiths continues to work from time in Wales, and his last contribution was as Assistant Producer on the live six-day coverage for S4C of the Urdd Gobaith Cymru Eisteddfod from the Conwy Valley held in May 2008. He has previously worked on the 2006 and 2007 festival broadcast.

In 2000, Griffiths received several writing commissions from S4C including his first feature film commission. Two other scripts had also been turned into short dramas for the Welsh-language channel. He has worked on a number of scripts for S4C series like Pengelli and Tipyn o Stad (A Bit of a State) and wrote a 13 episode children’s animation series called Bibi Bêl (Bibi the Ball) for Griffilms. His work is inspired by everyday life and gets his inspiration from listening to people talking and picking things up from conversations. In 2000, S4C's commissioning editor for drama, Angharad Jones said Griffiths’ scripts contained warmth and a sense of humour. “He also has quite a good understanding of female characters as he has got sensitivity”, she added.

After his Youth Company parted in 1994, Griffiths was invited to co-write, produce and direct a musical for a Festival to celebrate the centenary of poet and Archdruid Cynan in Pwllheli, Wales. In collaboration with Musical Director and Composer Annette Bryn Parry and author Glyn Roberts, Griffiths successfully produced O Docyn Brwyn i Ben Draw’r Byd (From ‘Tocyn Brwyn’ to the Ends of the Earth) at Neuadd Dwyfor Theatre, Pwllheli in May 1995, with a cast of over 50 local and professional artists including the Hogia’r Wyddfa and Rosalind and Myrddin. Following the success of the production, an annual May Festival was set up in the town, and Griffiths co-wrote and directed three further productions with the cast; Dan Hwyl Wen (Under a White Sail) in 1996 based on the sea-shanties of J.Glyn Davies, Dan Gysgod y Graig (In the Shadow of the Rock) in 1997 based on the true story of the Carreg yr Imbyll Granite Company, and Ail-Godi’r Llen (Raising the Curtain) in 2005, to celebrate the tenth anniversary of the company.

In 1998, Griffiths was commissioned along with composer Einion Dafydd to write a musical for the Urdd Gobaith Cymru Eisteddfod in Pwllheli, and Yn y Ffrâm (Framed) was produced at Neuadd Dwyfor, during the festival week in May 1998. A second commission followed in 2000, and Griffiths worked with composer Gareth Glyn on Ail-Liwio'r Byd which was staged at the Venue Cymru, Llandudno in May 2000.

Since re-locating to London in June 2007, Griffiths has worked as a production assistant on Moonwalking in Chinatown at the Soho Theatre, The Masque of the Red Death at the Battersea Arts Centre, and musical productions with UK.

Since March 2006, Griffiths has contributed a controversial weekly theatre column to the National Paper of Wales Y Cymro. His frank and honest comments were well received, and gained the respect of many actors and theatre directors. He openly disagreed with the appointment of Cefin Roberts, as the Artistic Director of the National Theatre of Wales, and received much criticism for his honest remarks. He often declared his jealousy of the National Theatre of Scotland, under the leadership of Artistic Director Vicky Featherstone and longed that Wales could one day match their production standards.

Griffiths regularly has to defend his views, especially in respect to the Welsh language National Theatre of Wales on numerous arts programmes on BBC Radio Wales and S4C. In February 2010, Griffiths was interviewed on S4C's youth current affairs series Hacio in which he defended his right to criticise the work of the Theatr Genedlaethol, on an artistic level.

To date Griffiths has covered well over 300 productions from Wales to London's West End and the Edinburgh Fringe Festival.

In July 2008, Griffiths became Operations Manager for UK and managed their 2008 Summer productions which included Marie Jones' The Chosen Room at Belfast, Terry Pratchett' Mort at the Yvonne Arnaud Theatre, Guildford and Nick Stimson and Jimmy Jewell's production of Peter Pan at the Barbican, Plymouth. YMT's production of Conor Mitchell and Kath Burlinson’s Missing Mel transferred to the Cochrane Theatre in the West End in October 2008.

Griffiths' Summer 2009 productions include A Winter's Tale by Howard Goodall and Nick Stimson at the Yvonne Arnaud Theatre, Guildford, Loserville - The Musical by James Bourne and Elliot Davis at the South Hill Park Arts Centre in Bracknell with Mamma Mia! Musical Director Martin Lowe and second year developments of Marie Jones' The Chosen Room in Belfast and Peter Pan at the Aberdeen International Youth Festival. YMT will also be commissioning four new musicals called Fool's Gold and According to Brian Haw...? at the Barbican, Plymouth,The Watchers at the Bradford Playhouse and EIGHT at Casterton in Cumbria. In December 2009, Peter Pan transferred to the Bridewell Theatre, London for a short pre-Christmas run.

In February 2010, Griffiths appeared on S4C's early evening TV show 'Wedi 7' to promote YMT's 2010 Cardiff Auditions.

YMT's 2010 Summer productions, which Griffiths will oversee, include further development of Nick Stimson and Jimmy Jewell's Peter Pan which again is destined for a pre Christmas London run, and their new interpretation of John Gay's The Beggar's Opera at South Hill Park Arts Centre in Bracknell. Other projects include Jen Toksvig's adaptation of David Almond's children's novel, The Savage in Casterton, Cumbria; Scheherazade at the Bradford Playhouse; A Song for Eurydice at the Barbican Plymouth and a sequel to the 2009 production of the vampire musical The Watchers called Ghosts of the Past at the Aberdeen International Youth Festival.