She was born in Brooklyn, New York, the eldest of three daughters of Herman Triebitz (1877–1943) and Bertha Hert (1885–1967). Her sisters were Sylvia Triebitz (1911–1949) and Mildred "Mimi" Triebitz (1918–?) Her parents were born in Austria, and immigrated to the United States. Their native language was Yiddish. He was the proprietor of a shoe store in Brooklyn, and later sold shoes wholesale.
Dorothy attended Cornell University in Ithaca, New York. Taking the stage name Dorothy Tree, she began her acting career on the stage in 1926. She appeared in six plays on Broadway, including her role as Jessica (Shylock's daughter) in The Merchant of Venice (1930).
Tree made her motion picture debut playing a department store employee in the Famous Players-Lasky/Paramount Pictures silent era romantic comedy It (1927) starring Clara Bow and Antonio Moreno. Tree next played a wife of Bela Lugosi's Dracula (1931); she also played a bride of Dracula in the Spanish language version of the same title, which was shot at night with a different cast using the same sets at Universal.
She married on 8 June 1928, in Manhattan, New York, screenwriter and story editor Michael Uris (March 25, 1902–July 17, 1967). They had one son, Joseph M. Uris (born October 25, 1943).
Tree attracted attention as a feminine menace on the screen as the hairdresser-spy, Hilda Kleinhauer, in the Warner Bros. drama Confessions of a Nazi Spy (1939) starring Edward G. Robinson, which won the National Board of Review Award for Best Film – English Language. Her performance immediately won her the role as Reni Vonich, head of a spy ring attempting to steal the latest in technology, in Paramount's sci-fi drama Television Spy (1939). She was signed by RKO to portray the important role as Elizabeth Edwards, Mary Todd's sister, in Abe Lincoln in Illinois (1940) starring Raymond Massey.
She portrayed Martha Rockne in the Warners biopic Knute Rockne, All American, the mother of the famous football coach played by Pat O'Brien. The movie also stars Ronald Reagan and Gale Page. In MGM's film noir crime/drama The Asphalt Jungle Tree played May Emmerich, a bedridden woman who is the very ingenuous and frustrated wife of Alonzo Emmerich (played by Louis Calhern), a crooked lawyer and double-crosser who, although he truly loves May, is having an adulterous affair with the character played by Marilyn Monroe.
Tree also appeared as Aunt Martha Dale in a teleplay of the live television anthology series The Silver Theatre (1950), which was titled Minor Incident. Her last role on the theater screen was as Marie Elsner in Columbia's crime/drama The Family Secret (1951) starring John Derek and Lee J. Cobb.
In 1952, Tree and her husband, Michael Uris, were branded as communists and blacklisted due to the HUAC testimony of playwright/screenwriter Bernard C. Schoenfeld.
She then began a second career teaching voice and diction in New York. She specialized in singing in English at the Metropolitan Opera and the Mannes College of Music, and also taught at the Manhattan School of Music, using her married name, Dorothy Uris. She was quoted as saying, "I left Dorothy Tree in Hollywood."
On November 4, 1956, an article written by Uris about English singing with good diction and its aiding a singer to clarify words for the listener was published in the New York Times. She published four books, Everybody's Book of Better Speaking (1960); To Sing in English, a Guide to Improved Diction (1971); A Woman's Voice: A Handbook to Successful Private and Public Speaking (1975); and Say it Again: Dorothy Uris' Personal Collection of Quotes, Comment & Anecdotes (1979).
Dorothy Tree Uris died at age 85 of heart failure at the Actors Fund of America Nursing Home in Englewood, New Jersey.