Jones has appeared in various television series, including Fat Friends (2000–2005), Little Britain (2003–2007), Nighty Night (2004–2005), Saxondale (2006–2007) and The Street (2009).

[6] After graduating from University of Warwick with a degree in Theatre Studies and Dramatic Arts, she trained at the Royal Welsh College of Music & Drama in Cardiff.

In 1990, however, the comedian and pantomime producer Stan Stennett offered her an Equity contract, shifting scenery and playing a Teenage Mutant Ninja Turtle (Michelangelo) in Dick Whittington at the Grand Pavilion, Porthcawl where she had performed in school musicals.

[citation needed] In October 2018 Jones returned to the stage, after a 12-year absence, in the new play Nightingale by William Gaminara, produced by Jenny Topper at the Theatre Royal, Bath.

[citation needed] In Summer 2024 Jones played the role of Mother Superior in the West End production of Sister Act at the Dominion Theatre, alongside Beverley Knight, Alexandra Burke and Lizzie Bea.

[citation needed] Her first television job was an unbroadcast sketch show for BBC Wales, which included Rob Brydon and Steve Speirs.

In 1996, she appeared in the BBC television period drama Drover’s Gold, billed as a "Welsh Western" which told the story of a cattle drive from West Wales to London.

"[9] Jones appeared on television as Kelly in four series of ITV's comedy Fat Friends, where she met James Corden.

[10] Jones achieved prominence in 2007 as co-writer with James Corden of the BBC Three sitcom Gavin & Stacey, and playing the lead role of Nessa Jenkins.

[11] In 2008 Jones featured in two BBC One television period costume dramas, Tess of the d'Urbervilles and Little Dorrit, as well as two episodes of The Street.

In 2010, she starred in BBC Four comedy The Great Outdoors alongside Mark Heap, and, in December, presented the first of four chat shows on BBC2, Ruth Jones' Christmas Cracker.

It was Jones' first major comedy project since Gavin & Stacey; she created, executive produced and storylined the show with Peet.

In January 2018 Jones took the part of Mandy Haveez in Radio Wales comedy series Splott, written by David Peet and made by Tidy Productions.

[citation needed] In 2020 she participated in Iaith ar Daith ('Language Road Trip'), a show for S4C where she and several other celebrities learned Welsh, broadcast in April 2020.

[16] Once again teaming up with James Corden, together they wrote and starred in the final episode of Gavin & Stacey airing on Christmas Day 2024 on BBC One, 17 years after the show was first broadcast.

[24] In 2010, Jones took part in Channel 4's Comedy Gala, a benefit show held in aid of Great Ormond Street Children's Hospital, filmed live at the O2 Arena in London on 30 March.