He was born on August 24, 1898 in Belsano in Cambria County, Pennsylvania to William Cowley, a homeopathic doctor, and his wife, Josephine Hutmatcher.

His father practiced at a clinic in Pittsburgh and so he grew up in the East Liberty neighborhood of Pittsburgh. He was fond of Belsano, where the family used to spend their summers.

He received his early education from the Peabody High School, Pittsburgh, Pennsylvania and became friends with Kenneth Burke, who later became a literary theorist. Later in life, he recalled being in school as the best time of his life. He graduated from high school in 1915.

In 1915, he won a scholarship to study at the prestigious Harvard University and started his graduation studies. In 1917, his studies were interrupted by the World War I and he served as an American Ambulance truck driver in France. He also wrote articles regarding the World War I in Pittsburgh Post-Gazette.

In 1918, he returned to America to complete his graduation. He obtained his Bachelor Degree in Arts, cum laude, in 1920. Then, he moved to France to pursue advance studies at the University of Montpellier.

While in France, he became friends with the writers of ‘Lost Generation’ such as Ernest Hemmingway, F. Scott Fitzgerald, Ezra Pounds, Edmund Wilson and many others. Alongside his studies, he found work with the avant-grade literary magazines such as ‘Broom’ and ‘Secession’.

In 1923 he returned to America and was hired by the Sweet's Architectural Catalogue in New York City for the post of advertising copywriter and translator in 1925. He worked there till 1929 and also translated seven books from French to English.

In 1929, he became the literary editor of ‘The New Republic’, a post he assumed for the next 11 years. He also published his first collection of poetry, ‘Blue Juniata’, in 1929 and earned himself a distinct reputation as a poet.

In 1934, he published his autobiographical non-fiction book, ‘Exile’s Return: A Narrative of Ideas’. It depicted the experiences of expatriate American writers in 1920s and the significance of rediscovery of America as a literary source.

In 1935, he, along with some other writers, formed the League of American Writers and became its vice-president. He took part in the campaign to convince U.S. government to support the republicans in the Spanish Civil War. He resigned from the post in 1940.

In 1941, he published his second collection of poems, ‘The Dry Seasons’. During the 1940s, he became the editor and literary adviser of the Viking Press, a post he held until 1985. He edited the works of some of the most prolific authors such as Ernest Hemmingway, William Faulkner and Nathaniel Hawthorne.

In 1954, he published his portrayal of American writers in the society, ‘The Literary Situation’. In the fall of 1960, Cowley taught the Stegner Fellowship graduate class at Stanford University.

His other non-fiction works include ‘Think Back On Us’ (1967), ‘A Many-Windowed House’ (1970), ‘And I Worked at the Writer’s Trade’ (1978), ‘The Dream of the Golden Mountains: Remembering the 1930s’ (1980) and ‘The View from Eighty’ (1980).

Among his edited works were the ’The Portable Faulkner’ (1946), ‘The Portable Hawthorne’ (1948) and ‘’The Complete Poetry and Prose of Walt Whitman’ (1948).

One of his most notable works was the editing of William Faulkner’s collection of short stories, ‘The Portable Faulkner’, in 1946. It established Faulkner as one of the greatest writers of all time and Faulkner expressed his gratitude for Cowley’s significant contribution as the editor of the book.

His other major work is ‘And I Worked at the Writer’s Trade’ in 1978 which is primarily autobiographical with elements of literary history.

In 1939, he received the ‘Harriet Monroe Memorial Prize’ for his poetry.

In 1980, he was honored with the ‘National Book Award for Biography’ for his exceptional work, ‘And I Worked at the Writer’s Trade’.

He also received the ‘National Institute of Arts and Letters Gold Medal’ in 1981.

He married “Peggy” Marguerite Frances Baird, a landscape painter in August 1919 during his graduation years at Harvard University. They traveled to France after his graduation and returned to U.S in 1923. They got divorced in 1931.

In June 1932, he married Muriel Maurer and they were blessed with a son, Robert William Cowley. Their son became an editor and a military historian later in life.

He passed away on March 27, 1989 due to a heart attack, at New Milford, Connecticut, U.S.A.