Sophia Williams-De Bruyn (born 1938) is a former South African anti-apartheid activist.
Born in Port Elizabeth, Eastern Cape, Williams-De Bruyn rose from working in the Van Lane Textile factory to become an executive member of the Textile Workers Union in Port Elizabeth. She was a founding member of the South African Congress of Trade Union (SACTU), the predecessor of the Congress of South African Trade Union (COSATU). In 1955, she was appointed as a full-time organiser of the ‘Coloured People’s Congress’ in Johannesburg.
On August 9, 1956, she led the march of 20 000 women on the Union Buildings of Pretoria along with Lilian Ngoyi, Albertina Sisulu, and Helen Joseph to protest the requirement that women carry pass books as part of the pass laws. She is the last living leader of the march.
The recipient of numerous awards, she is currently a provincial legislator in Gauteng Province for the ANC.