Ethel Emma McMillan QSO JP (née Black, 12 May 1904 – 13 August 1987) was a New Zealand politician of the Labour Party.

She lectured in history at Otago for a year, during which time she met the medical student and her future husband, Gervan McMillan.

[2] During their time in Kurow, the McMillans had friendships and political discussions with their neighbours, Arnold Nordmeyer and Jerry Skinner; both would become influential MPs for the Labour Party.

She had governance roles with the Dunedin Public Art Gallery Society, the Otago Museum Trust, and the New Zealand Library Association.

[1] Three short streets close to the University of Otago campus were renamed in 1993 (New Zealand women's suffrage centenary year) to honour McMillan, Emily Siedeberg, and Ethel Benjamin.