S. O. Davies, Welsh union leader and politician (d. 1972)
Stephen Owen Davies (c. 1886 – 25 February 1972) was a Welsh miner, trade union official and Labour Party politician, the Member of Parliament (MP) for Merthyr Tydfil, previously Merthyr for nearly 38 years, from 1934 to 1972. In 1970, well past 80, he was deselected as parliamentary candidate by his local party association because of his age. He fought the election in the 1970 general election as an independent candidate and won comfortably, a rare example in British politics of an independent candidate defeating a major party's organisation. In a BBC TV interview the day after that election, he claimed to be 83 years old.

Most records show Davies's birth date as November 1886, but he is widely thought to have been born at least four years earlier. After leaving school aged 12 and working for some years in local pits, Davies studied mining engineering and later took an Arts degree at University College, Cardiff. He returned to the coalfields in 1913, and established a reputation for militancy. In 1918, he was elected miners' agent for the Dowlais district of the South Wales Miners' Federation (SWMF), and in 1924 was appointed SWMF's chief organiser, legal adviser, and vice-president. After a visit to Moscow in 1922, he became a firm advocate for the Soviet Union, a position he maintained for the rest of his life.

After his election to parliament in 1934, Davies was a consistent advocate for the interests of Merthyr Tydfil and mining in Wales. Largely indifferent to party discipline, he defied official Labour policy by championing such causes as disarmament and Welsh nationalism. His persistence in doing so brought him several suspensions from the party, and he was never offered ministerial office. An immensely popular figure locally, he was regularly returned at general elections with large majorities. In 1966, after the Aberfan disaster and loss of 144 lives, Davies controversially stated that he had long thought that the tip was unsafe. He had not reported his suspicions, for fear that an inquiry would cause the closures of local pits.

Davies died in 1972, aged at least 85, and possibly over 90.