Thomas Lanier Williams III was born of Welsh and Huguenot descent, in Columbus, Mississippi, the second child of Edwina and Cornelius Williams.:11 His grandfather, Walter Dakin, was the local Episcopal priest, and his maternal grandmother, Rose O. Dakin, was a music teacher. His father was a hard-drinking traveling shoe salesman who spent most of his time away from home. His mother, Edwina, was an archetype of the ‘Southern belle’, whose social aspirations tilted toward snobbery and whose behavior could be neurotic and hysterical. Shortly after his birth, his grandfather Dakin was assigned to a parish in Clarksdale, Mississippi and Williams' early childhood was spent in the parsonage there.
His family included an older sister Rose (1909–1996), and a younger brother, Dakin (1919–2008). ‘Tom’, as he was called in his youth, developed a close bond with his sister. Born only sixteen months apart, theater scholar Allean Hale notes that they were “as inseparable as twins, sometimes referred to as ‘The Couple’.”:11Rose and their negro nursemaid, Ozzie, were his only companions as a child. Hale speculates that growing up in a female-dominated environment gave Williams empathy for the woman characters he created as a playwright. Shy, fragile and predisposed to emotional disturbances, eventually to the point of mental illness, Rose inspired a host of characters in his fiction.:x
As a small child Williams suffered a bout of diphtheria which nearly ended his life and left him weak and virtually confined to his house during a period of recuperation that lasted a year. At least in part as a result of his illness, he was less robust as a child than his father would have wished. Cornelius Williams was a descendant of east Tennessee pioneer stock (hence Williams’ professional name) and a man prone to use his fists. He disdained his son’s effeminacy and his mother Edwina, locked in an unhappy marriage, focused her overbearing attention almost entirely on Tom. Williams would find inspiration in his dysfunctional family for much of his writing.