Jemma Gwynne Griffiths (born 18 May 1975), known by her stage name Jem, is a Welsh singer, songwriter, and record producer.

Born and raised in Penarth, Glamorgan, she began songwriting at an early age. After graduating from university in 1996, she worked as a DJ as well as co-founder of record label Marine Parade in Brighton. On 24 March 2004, she released her debut studio album Finally Woken through ATO Records. Featuring the singles "They", "Just a Ride" and "Wish I", the album saw the most success in the United Kingdom, where it was certified Platinum. Jem followed up her debut with her second album, Down to Earth, released on 18 September 2008. Her third album, Beachwood Canyon, was released in 2016.