Margaret Constance Williams was born in Bristol on 15 April 1997 to Hilary Pitt (now Hilary Frances), a university course administrator who later quit her job to support her daughter's acting career. Williams' parents separated when she was four months old. The youngest of four siblings, Williams was raised by his mother and stepfather in a three-bedroom council house in Clutton Village, Somerset.
From an early age, when she was "younger", Williams was always referred to as "Macy", due to her perceived similarity to the cartoon character of the UK newspaper comic strip The Parishors. Williams Midsomer attended Cloughton Primary School and Norton Hill School in Norton, before transferring to Bath Dance College to study performing arts, where she trained in musical theater, ballet, pointe, tap, street, freestyle, gymnastics and trampolining. Liya, with the ambition to become a professional dancer, taught her at home for two years. She left school at the age of 14 before taking her final secondary school exams (which predicted her to achieve a higher grade), partly due to personal difficulties she experienced going to her regular school While starring in a popular television series. Her acting career started successfully.
At the age of 12, Williams began her professional acting career by co-starring in one of the biggest ensemble casts on television. She was cast in the role of Arya Stark, a feudal youth samadhi of an important aristocratic family in HBO's historical fantasy drama series Game of Thrones (based on George RR Martin's A Song of Ice and Fire fantasy novel series). Williams almost missed the audition (her second ever) ever since it happened with a school trip, her mother convinced her to go to the audition. The international popularity of Game of Thrones brought Williams global recognition as the series viewership grew. Described as a fan favorite and central protagonist in the Game of Thrones fantasy epic, Arya's first six seasons feature a story arc that covers seriousness, trauma, tragedy, and revenge. Williams, Those who did most of their own stunt and fight scenes in the series are naturally right-handed but remained in character by performing left-handed in the show. Williams appeared in all eight broadcast seasons of Game of Thrones, the last episode of which aired in May 2019.