Blanche Sweet was born as Daphne Wayne, from show business parents. She joined the act before she was four years old and was very experienced by the time she came to the Biograph company in 1909. Blanche was trained in the movies by D.W. Griffith. He did something different with Blanche who was showcased in strong willed women. Of the many films she made with Griffith, some of her more memorable films were: A Corner in Wheat (1909), with Henry B. Walthall, Mack Sennett and Jeanie Macpherson; A Romance of the Western Hills (1910), with Mary Pickford, Dell Henderson and Kathlyn Williams; The Lonedale Operator (1911), with Wilfred Lucas and Dell Henderson; Judith of Bethulia (1914), starring Lionel Barrymore, May Marsh and Henry B. Walthall; and Home, Sweet Home (Reliance/Majestic, 1914), with Spotiswoode Aitken, Dorothy Gish and Josephine Crowell.

In 1915, Blanche joined the Lasky Feature Play Company, where she made films under many well known directors of the era, The Warrens of Virginia (1915), The Ragamuffin (1916); and The Storm (1916). 1917 she found a new director at Famous Players-Lasky, and a new love in the personage of one Marshall Neilan. Their first picture together was Those Without Sin (1917), with Charles Ogle. They married several pictures later, in 1922. By this time, both Blanche and Charles Ogle were well established stars.

Charles and Blanche, it was her role as the Swedish prostitute in Anna Christie (Thomas H. Ince Corp., for First National, 1924), with William Russell. Other films would follow, Tess of the D'Urbervilles (M-G-M, 1924), with Conrad Nagel and directed by her husband Neilan. Neilan would direct her again The Sporting Venus (M-G-M, 1925), with Ronald Colman, and Diplomacy (Famous Players-Lasky, 1926), with Neil Hamilton and Matt Moore. This would be their last film together. By this time Blanche's marriage was failing would divorce in 1929.

Blanche continued into the sound era briefly and after 1929 made only three talkies: Show Girl in Hollywood (First National, 1930), starring Alice White; The Silver Horde (RKO Pictures, 1930), with Evelyn Brent and Louis Wolheim and The Woman Racket (M-G-M, 1930), with Tom Moore. Blanche retired from the screen, but continued her stage career and performed for years in Vaudeville and stock companies. Her act consisted of singing, comedy skits and her famous role in Anna Christie. In 1936 she married again to actor Raymond Hackett.

After 1958, and not having any children by both marriages, Blanche was a saleswoman in a department store. She made a return to the to movies for one film, The Five Pennies (Paramount, 1959), starring Danny Kaye. In the 1960's Blanche became a film historian. Blanche Sweet was an intrical part of the re-forming of the Biograph company in 1986. Her tireless advice and help made it possible for the Biograph company to be re-opened in its former glory. She helped many researchers studying Hollywood history and looking for the survivors of the silent era. She returned to New York City to live, close to where she was raised as a child. She is gone, she is not forgotten. Blanche lives on through the spirit of the Biograph Company.