Shaw was born Irwin Gilbert Shamforoff in the South Bronx, New York City, to Russian Jewish immigrants. Shaw was a prolific American playwright, screenwriter, novelist, and short-story author whose written works have sold more than 14 million copies. He is best known for his novels, The Young Lions (1948) and Rich Man Poor Man (1970).
His parents were Rose and Will. His younger brother, David Shaw (died 2007), became a noted Hollywood producer. Shortly after Irwin's birth, the Shamforoffs moved to Brooklyn. Irwin changed his surname upon entering college. He spent most of his youth in Brooklyn, where he graduated from Brooklyn College with a Bachelor of Arts degree in 1934.
Shaw began screenwriting in 1935 at the age of 21, and scripted for several radio shows, including Dick Tracy, The Gumps and Studio One.
Shaw's first play, Bury the Dead (1936) was an expressionist drama about a group of soldiers killed in a battle who refuse to be buried. During the 1940s, Shaw wrote for a number of films, including Talk of the Town (a comedy about civil liberties), The Commandos Strike at Dawn (based on a C.S. Forester story about commandos in occupied Norway) and Easy Living (about a football player unable to enter the game due to a medical condition). Shaw married Marian Edwards. They had one son, Adam Shaw, born in 1950, himself a writer of magazine articles and non-fiction.
Shaw enlisted in the U.S. Army and was a warrant officer during World War II.He served with an Army documentary film unit. The Young Lions, Shaw's first novel, was published in 1949. Based on his experiences in Europe during the war, the novel was very successful and was adapted into a 1958 film.
Shaw's second novel, The Troubled Air, chronicling the rise of McCarthyism, was published in 1951. He was among those who signed a petition asking the U.S. Supreme Court to review the John Howard Lawson and Dalton Trumbo convictions for contempt of Congress, resulting from hearings by the House Committee on Un-American Activities. Falsely accused of being a communist by the Red Channels publication, Shaw was placed on the Hollywood blacklist by the movie studio bosses. In 1951 he left the United States and went to Europe, where he lived for 25 years, mostly in Paris and Switzerland. He later claimed that the blacklist "only glancingly bruised" his career. During the 1950s he wrote several more screenplays, including Desire Under the Elms (based on Eugene O'Neill's play) and Fire Down Below (about a tramp boat in the Caribbean).
While living in Europe, Shaw wrote more bestselling books, notably Lucy Crown (1956), Two Weeks in Another Town (1960), Rich Man, Poor Man (1970) (for which he would later write a less successful sequel entitled Beggarman, Thief) and Evening in Byzantium (made into a 1978 TV movie). Rich Man, Poor Man was adapted into a highly successful ABC television miniseries in 1976.
His novel Top of the Hill, about the Winter Olympics at Lake Placid in 1980, was made into a TV movie, starring Wayne Rogers, Adrienne Barbeau, and Sonny Bono.
His last two novels were Bread Upon the Waters (1981) and Acceptable Losses (1982).
Shaw died in Davos, Switzerland on May 16, 1984, aged 71, after undergoing treatment for prostate cancer.