Miller was born in Montour and grew up in Marshalltown, where he spent an unhappy childhood during the Depression. As an unathletic boy who wore thick glasses and played the violin and piano, he was called a sissy when he started to school, and "I heard that word at least five days a week for the next 13 years until I skipped town" and went away to college, he said.
At the University of Iowa, he wrote a popular, satirical column in the Daily Iowan, was a radio commentator on WSUI, and in 1938 won a scholarship to study at the BBC in London. Later, during World War II, he became editor of Yank magazine. By 1949 he was editor of Harper's magazine. He was married for more than four years to Elinor Green.
His first best-seller was the novel That Winter, published in 1948. Marshalltown, Iowa was about his growing-up years.
Miller wrote the screenplay for Kings Go Forth, a 1958 Frank Sinatra movie. He enjoyed major success with Only You, Dick Daring! a humorous account of writing for TV.
Merle Miller hated being called a sissy. He ended up doing a courageous thing: He came out of the closet with a milestone article in the New York Times magazine in 1971. In writing "What It Means to Be a Homosexual," Miller was among the first notable Americans to discuss their homosexuality.
An expanded version of the article was published in book form that year, titled On Being Different.
Miller achieved acclaim with Plain Speaking, An Oral Biography of Harry S. Truman in 1974. He followed that with Lyndon: An Oral Biography in 1980, profiling President Johnson.
Miller, who lived near Brewster, N.Y., died in Danbury, Conn., of complications of abdominal surgery. He died before he was able to complete a biography of President Eisenhower, although a portion was published as Ike, the Soldier.