Johanna Catharina Cornelius (27 February 1912 – 21 June 1974) was an Afrikaner activist and trade unionist.
She served as the Afrikaner Garment Workers' Union of South Africa (GWU) president after Solly Sachs.
[2] She and her older sister, Hester Cornelius, moved to Johannesburg in the 1920s, where Johanna eventually started working in a garment factory.
[2] Cornelius was accused in 1938 of being a "communist accomplice of Sachs and for spending all her time organising black people.
[1] She became a founder of the National Union of Cigarette and Tobacco Workers in 1938, later leading a two-week strike in Rustenburg in September 1940.