Heller was born on May 1, 1923 in Coney Island in Brooklyn, New York, the son of poor Jewish parents, Lena and Isaac Donald Heller, from Russia. Even as a child, he loved to write; as a teenager, he wrote a story about the Russian invasion of Finland and sent it to the New York "Daily News", which rejected it. After graduating from Abraham Lincoln High School in 1941, Heller spent the next year working as a blacksmith's apprentice, a messenger boy, and a filing clerk.