Ann Griffiths (née Thomas) (April 1776 – August 1805) was a Welsh poet and writer of Methodist Christian hymns.

Ann was born in April 1776 near the village of Llanfihangel-yng-Ngwynfa, six miles from the market town of Llanfyllin (in the former county of Montgomeryshire) in Powys. She was the daughter of John Evan Thomas, a tenant farmer and churchwarden, and his wife, Jane. She had two older sisters, an older brother, John, and a younger brother, Edward. Her parents' house, Dolwar Fechan, was an isolated farm-house some two-and-a-half miles south of Llanfihangel and one mile north of Dolanog, set among hills and streams. Not far away lay Pennant Melangell, where Saint Melangell had lived as a hermit in the 8th century.

Ann was brought up in the Anglican Church; but in 1794, when she was eighteen, her mother died, and about this time or perhaps earlier she followed her brothers John and Edward in becoming drawn to the Methodist movement. In 1796 she joined the Calvinistic Methodist movement after hearing the preaching of Rev. Benjamin Jones of Pwllheli.

Marcia Llyneth Griffiths (born 23 November 1949, Kingston, Jamaica) is a successful female singer, also called the "Queen of Reggae". One reviewer described her noting "she is known primarily for her strong, smooth-as-mousse love songs and captivating live performances".

Griffiths started her career in 1964. From 1970 to 1974 she worked together with Bob Andy in the group Bob and Marcia, on the Harry J label. Between 1974 and 1981 she was a member of the I Threes, a background group, which supported Bob Marley & the Wailers.

Her song "Electric Boogie", released in 1976 and re-released in 1989, made the Electric Slide, a line dance, an international dance craze. It reached number 51 on the US Billboard Hot 100 making it her most successful single. It remains the highest-selling single by a female Reggae singer of all time.^{[citation needed]}