Dorothy Helen Ruth Pirone (June 7, 1921 – May 18, 1989) was the biological daughter of Babe Ruth and his mistress Juanita Jennings (born Juanita Grenandtz). She was adopted by Babe and his first wife, Helen Woodward Ruth. She wrote a memoir of her father, titled My Dad, the Babe.
Dorothy was born June 7, 1921 in New York City, at St. Vincent's Hospital to Juanita Jennings, and was adopted by Babe and Helen Ruth. It is documented that Dorothy was raised to believe that Helen was her biological mother. It is speculated that Helen did not know that Dorothy was the result of an extramarital affair between Babe and his girlfriend, Jennings. It is possible that when Babe Ruth learned of his mistress's pregnancy, he convinced Helen, unaware that Babe was the father, to adopt the baby girl. Babe Ruth also somehow convinced Dorothy's biological mother to allow him to adopt their daughter, so that she could be raised with him and a (possibly unsuspecting) Helen.
Helen and Babe Ruth separated some time between 1924–1926. Babe and Helen Ruth did not divorce because of their religious beliefs. Dorothy lived with her adoptive mother Helen after the separation. In January 1929, when she was 7 years old, her mother died in a house fire. After Helen's death, Dorothy lived with her father and Claire Merritt Ruth, whom he married in April 1929. She had one half-sister, as Babe had adopted Claire's daughter Julia.
Dorothy learned at the age of 59 in 1980 that Juanita Jennings Ellias was her real mother. Dorothy had known Juanita growing up, but only as a friend of her father. She had never known that Jennings was her biological mother. She referred to Jennings as "Aunt Nita." 
She married Daniel J. Sullivan, a Brooklyn employee of the Railway Express Agency, on January 7, 1940. Her son, Daniel J. Sullivan Jr. (1940 - 1974), (Ruth's first grandchild) in October 1940, and later had 5 other children. Dorothy's marriage to Sullivan also produced two daughters, Genevieve and Ellen Ruth Hourigan (b. 1943), before the union ended in 1945. Dorothy later married Dominick Pirone, a New York general contractor in New York City, on December 8, 1948. Three children were born of this second marriage, Donna, Richard Pirone (1950-2001), and Linda Ruth Tosetti (b. 1954). She lived in Durham, Connecticut and raised Arabian horses, and wrote My Dad, the Babe.
She died on May 18, 1989 at the age of 67 in Durham, Connecticut, survived by four daughters, a son and 12 grandchildren.
- "Dorothy R. Pirone, 68, Babe Ruth's Daughter" The New York Times, May 20, 1989. Accessed August 7, 2012.
- Rogoff, Herb. "Ruth & his women" One More Inning (online magazine) at baseballguru.com. Accessed August 7, 2012.
- ALTAVILLA, JOHN. "Babe's Power Still Carries: Granddaughters Keep Ruth's Legend Alive, Tangled Though It Is". Hartford Courant. Retrieved 12 July 2014.
- Pirone, Dorothy Ruth; Chris Martens (1988). My Dad, the Babe: Growing Up with an American Hero. Boston: Quinlan Press. ISBN 1-55770-031-1. OCLC 17652057.
- My Dad, the Babe entry at the Library of Congress
- Dorothy Ruth Pirone, et.al. v. Macmillan, Inc., No. 89-7750, U.S. Court of Appeals for the Second Circuit, 894 F.2d 579; 1990 U.S. App. LEXIS 1301. February 13, 1990. pdf accessed August 7, 2012.