John Rhys-Davies was born on 5 May 1944 in Salisbury, England, to Welsh parents: his mother, Phyllis Jones, was a nurse, and his father, Rhys Davies, was a mechanical engineer and colonial officer. His father's postings took the family to Tanganyika (now part of Tanzania) for much of his early childhood, before they settled in the Welsh town of Ammanford, Carmarthenshire, where Rhys-Davies was raised.
He was educated at Truro School in Cornwall and the University of East Anglia, where he was among the university's first 105 students and co-founded its drama club, before training at the Royal Academy of Dramatic Art in London. Early television work included I, Claudius (1976) and the acclaimed 1980 miniseries Shogun, for which he received a Primetime Emmy nomination.
Rhys-Davies became a household name playing Sallah, ally of Indiana Jones, in Raiders of the Lost Ark (1981), Indiana Jones and the Last Crusade (1989) and, decades later, Indiana Jones and the Dial of Destiny (2023). He achieved further global fame as the dwarf Gimli — and voiced the Ent Treebeard — in Peter Jackson's The Lord of the Rings trilogy (2001-2003), sharing in the cast's Screen Actors Guild Award for The Return of the King. He also led the cast of the science-fiction series Sliders as Professor Maximillian Arturo from 1995 to 1997.
In 2013, Rhys-Davies explored his Welsh roots further on the BBC genealogy programme Coming Home, discovering details of his grandfather's work in the Carmarthenshire coal mines, and has spoken publicly of being "very proud of being a Welshman."