Leonore (Ella) Sophie Winter Steffens Stewart (1898–1980) was an Australian-British journalist and activist.
Her parents were Freda Lust and Adolph Wertheimer from Nuremberg (Nürnberg) in Germany, who lived in London, Melbourne, Australia and again in London, when they changed their name to Winter (around 1910). Their children Rudolph, Rosa and Eleanora (Ella) were born in Melbourne. Fredric Wertham was a relative. She studied at the London School of Economics in England.
She met the U.S. journalist and 'muckraker' Lincoln Steffens at the Versailles Conference, where she was secretary to US Supreme Court Justice Felix Frankfurter. Winter and Steffens married in 1924. They moved to Italy, where their son, Peter, was born in San Remo.
Two years later, they moved to the largest art colony on the Pacific Coast, Carmel-by-the-Sea, California, where their friends and neighbors included photographer Edward Weston, poet Robinson Jeffers, philosopher/mythologist Joseph Campbell, nutritionist/author Adelle Davis, short story writer/poet Clark Ashton Smith, marine biologist/ecologist Ed Ricketts, Nobel prize winner Sinclair Lewis, and novelists John Steinbeck and Henry Miller. Carmel was sharply divided between conservative and liberal factions; the latter quickly coalesced around the Steffens, who publicly debated the most controversial topics. The Irish poet and folklorist Ella Young, as well as the local press, described the relaxed social intercourse in this counterculture world.  In 1928 the Steffens helped to create The Carmelite, a publication that was offered as an alternative to the town’s somewhat stodgy local paper, the Carmel Pine Cone. With contributions by numerous leftist literati, including Jeffers, Martin Flavin, Lewis and the Steffens, along with theatre, dance and art reviews by feminist artists such as Alberta Spratt, Jennie V. Cannon and Roberta Balfour, The Carmelite became one of California’s most controversial publications. Its illustrations ranged from Weston’s enigmatic photos to the “anarchist” prints of James Blanding Sloan. The Steffens also arranged for public exhibits of Europe’s most avant-garde art, including Dada, Surrealism and the paintings of Paul Klee. Ella wrote on various topics and once reported on the very unusual meeting between the popular Modernist artists John O’Shea and Frederick O’Brien. The Steffens support of the art community extended to their own home where they entertained local painters and offered to display their work. Ella loved publicity and when two Carmel reactionaries, artist William Silva and writer/editor Perry Newberry, tried to ban the local chapter of her “communist” John Reed Club as well as her “socialist reading room,” she made sure that the press as far away as Los Angeles was apprised of the violation of her civil rights.  The Steffens also joined controversial national campaigns, including the Scottsboro Boys Defense Fund which sought to free nine black men who were still incarcerated after the Supreme Court of the United States twice reversed their convictions for rape.   Lincoln Steffens died in Carmel in 1936.
She wrote her first book, Red Virtue, after visiting the Soviet Union. Her autobiography, And Not to Yield, was published in 1963. In 1939, Winter married the screenwriter and humorist Donald Ogden Stewart and became stepmother to his sons, Donald and Ames. They lived in California and then in Hampstead, London (misspelled by The New York Times as 'Hamstead').
- Red Virtue: Human Relations in the New Russia. Harcourt, Brace & Company, New York 1933
- Ella Winter, Granville Hicks (eds.): The Letters of Lincoln Steffens. Harcourt, Brace & Company, New York 1938
- I Saw the Russian People. Little, Brown and Company, Boston 1945
- Ella Winter, Herbert Shapiro (eds.): The World of Lincoln Steffens. 1962
- And Not to Yield: An Autobiography. Harcourt, Brace & World, New York 1963
- Edwards, Robert W. (2012). Jennie V. Cannon: The Untold History of the Carmel and Berkeley Art Colonies, Vol. 1. Oakland, Calif.: East Bay Heritage Project. pp. 48, 233, 548, 554–555, 558, 569, 627, 682. ISBN 9781467545679. An online facsimile of the entire text of Vol. 1 is posted on the Traditional Fine Arts Organization website ("Archived copy". Archived from the original on 2016-04-29. Retrieved 2016-06-07. ).
- Young, Ella (1945). Flowering Dusk, Things Remembered Accurately and Inaccurately. New York, NY: Longmans, Green & Co. pp. 297–301.
- Carmel Pine Cone: 1 November 1935, p. 6; 14 February 1936, p.11.
- The Carmelite, 3 April 1929, p. 3.
- Carmel Pine Cone, 19 April 1929, p. 14.
- The Carmelite, 14 April 1932, p. 9.
- Los Angeles Times, 22 April 1932, p. I-2.
- The San Francisco News, 24 February 1934, p. 11.
- Carmel Pine Cone, 23 February 1934, p. 5.
- The Oakland Tribune, 24 February 1934, p. 9.
- Cook, Joan (August 5, 1980). "Ella Winter Stewart, Journalist and Widow Of Donald O. Stewart; Was War Correspondent Back After 17 Years". The New York Times. Retrieved 2008-04-18.
Ella Winter Stewart, a journalist and the widow of Donald Ogden Stewart, who died Saturday, died of a stroke early today at her home in Hamstead, London. She was 82 years old.