Nir was born Juliusz Gruenfeld in Lwów, Poland, (present-day Lviv, Ukraine) on March 31, 1930.[1][2] He later changed his name to "Nir" after World War II since "Gruenfeld" has German origins.[1][2] Nir means 'plowed fields' in Hebrew.[2]
Nir released a memoir of his experience during the Holocaust, The Lost Childhood, in 1989.[1] A second edition was reprinted by Scholastic Press in 2002.[2]The Lost Childhood is now used as part of the high school curriculum throughout the United States.[2] He also published four self-help books focusing on relationships, including Not Quite Paradise: Making Marriage Work and Loving Men for All the Right Reasons.[2]
Yehuda Nir died at his home in Manhattan, New York City, on July 19, 2014, at the age of 84.[1] His funeral was held at Riverside Memorial Chapel on the Upper West Side, with burial on the Mount of Olives in Jerusalem.[2] He was survived by his wife Bonnie Maslin and their children: daughter Sarah, a reporter for The New York Times; and son David, the political director of Daily Kos; and two sons from a previous marriage: private investor Daniel and fashion executive Aaron.[1]