Her father, Captain Seton served in the British Army in India and South Africa. After the death of Captain Seton, Marie's mother, also named Marie, remarried Sir Charles Walpole.
In 1936, she helped her friend C. L. R. James, the Trinidadian writer and radical political activist, to put on his play about the Haitian Revolution, Toussaint Louverture, which starred Paul Robeson in the title role, with the Stage Society.
Seton's reconstruction of Sergei Eisenstein's projected epic, ¡Que viva México!, as a film released in 1939 entitled Time in the Sun, is considered by many critics as probably nearest to Eisenstein's concept because of her close relationship with the filmmaker.
She was a regular contributor to Sight and Sound and other publications.
Between 1938 and 1942 she was married to Donald Hesson, a Chicago lawyer and author.
According to her friend, Pamela Cullen, Seton "had a fascination for India and as a young woman she had been introduced to India's fight for independence by one of India's greatest political figures, Krishna Menon, who was then a struggling lawyer in London. She also had family associations with India through her father, who had served as an officer in the Indian Army and been seriously wounded during one of the many uprisings of the period".
Nehru invited Marie to India to help with the University Film Society and the Children's Film Society. She was probably recommended to him by D. G. Tendulkar, who must have known her during the time he was in Moscow studying cinema with Sergei Eisenstein. Over the years, Marie became a friend of Indira Gandhi. For some time in 1960s, Seton was a house guest of the Nehrus and stayed in Teen Murti.
Seton lived in India in the 1960s and 1970s and was actively involved in the film society movement, at the same time as being a close observer of Indian politics. She worked closely with Vijaya Mulay and Chidananda Dasgupta in establishing the Federation of Film Societies of India.
On her death, at her own request she was cremated, and the plaque of her ashes in Golders Green Crematotarium reads: "Marie Seton Hesson, Padma Bhushan, Citizen of the World".
Marie Seton--a tribute by Satish Bahadur. The Film Society Movement in India edited by H. N. Narahari Rao. Asian Film Foundation, Mumbai, India, 2009.