Keeping Faith (Welsh: Un Bore Mercher, "One Wednesday Morning") is a British thriller television series, filmed and set in Wales, and first broadcast in Welsh on S4C from 5 November 2017.

Created by Matthew Hall and produced by Vox Pictures. The series stars Eve Myles as Faith Howells, a solicitor at a family-run law firm whose husband, Evan, disappears whilst she is on maternity leave following the birth of their third child.

Renamed Keeping Faith, the English version premiered on BBC One Wales on 13 February 2018. The first series co-stars Hannah Daniel, Matthew Gravelle, Bradley Freegard, Mark Lewis Jones, Mali Harries and Aneirin Hughes. The show was extremely popular in Wales, with an average of 300,000 viewers per episode, making it the most popular show on BBC Wales for over 25 years and, with over 8.5 million downloads by May 2018, the most downloaded non-network show on BBC iPlayer.

Filmed concurrently in both languages, this series is the second in a season of bilingual dramas set to premiere back-to-back on S4C. The initial Welsh language broadcast on S4C carried entirely English subtitles, while repeat airings carried encoded English subtitles. The series has been available on the BBC iPlayer as part of the BBC's ongoing relationship with S4C.

On 15 June 2018, the BBC announced that Keeping Faith would be shown across the UK on BBC One, beginning on 10 July 2018. The Head of Commissioning for BBC Wales, Nick Andrews, said that the series had been "a real gem from start to finish", and a testament to the strength of drama coming out of Wales.

With series one ending with a cliff-hanger, Huw Thomas, the BBC Wales arts and media correspondent, wrote on 6 May 2018 that a second series is in development, and later that year, the second series was commissioned. Production began in September 2018 and broadcast in Wales, first in Welsh (with English subtitles) on S4C, from 12 May 2019; nationally shown on BBC One in English during July–August 2019.

The third and final series premiered on S4C (as Un Bore Mercher) in 2020 during November and December, and the English language broadcast began on BBC One on 27 March 2021. This series was made available on the BBC iPlayer on 27 March 2021. By May 2021 the series had had over 50 million views on BBC iPlayer.