Marie Brown (née Simpson; 1883[1] – 22 November 1949) was a medical doctor and activist in South Australia.
She married Dr. Gilbert Brown (14 August 1883 – 1960) that same day, and for a time lived and worked at Snowtown.
They had a son Ian on 29 May 1917 and lived for a while at Strangways Terrace, North Adelaide, then at 31 Watson Avenue, Rose Park for a few years.
Brown had a strong empathy with public health and women's and children's welfare organizations.
She was also honorary medical officer of the Kindergarten Union and a member of the National Council of Women.