A brilliant student, Davis received a Rhodes Scholarship to Queen's College, Oxford in 1910.
In 1906, at the age of 16, Davis entered Franklin College, where he served as editor of the school newspaper. That same year, he sold his first story to the Indianapolis Star for $25 and subsequently began work as the paper's Franklin correspondent. Davis earned a bachelor of arts degree from Franklin College in 1910, graduating magna cum laude.
Upon graduation, Davis was awarded a Rhodes Scholarship to study at Queen's College at Oxford University. While at Oxford, Davis studied Greek language, literature, and history. In 1911 he was awarded a master's degree from Franklin College for courses completed while in residence. Despite cutting his Oxford experience short by a year because of his father's deteriorating health and subsequent death, Davis managed to graduate from Oxford with a bachelor of arts degree in 1912. He was also able to spend a significant amount of time traveling around Europe.
Returning to the United States in 1913, Davis took a job as an editor for Adventure magazine. However, in early 1914, after only a few months on the job, he was offered a position as a junior reporter for the New York Times. Over the course of ten years, Davis moved from sports writing to become a foreign correspondent and editorial writer. In 1920 he created the cartoon Godfrey G. Gloom, who was a columnist and political commentator. Gloom became a popular character whose quick-witted remarks were highly popular among readers until Davis retired the cartoon in 1936. Along with working for the New York Times, Davis also began writing stories, novels, and political and historical essays. He published The Princess Cecilia (1913), History of the New York Times (1921), and the popular novel Times Have Changed (1923). On December 31, 1923, Davis quit his job with the Times to become a freelance writer. As a freelancer, Davis contributed stories and essays to such publications as Saturday Review of Literature, New Republic, Harper's, Liberty Magazine, and Collier's. He also continued to write novels, publishing nine fictional titles by 1936, several of which proved to be popular if not critically acclaimed, including the novel Love Among the Ruins (1935).
In 1936, with the world's eyes focused on Hitler's military aggression in Europe, Davis's attention turned to foreign affairs. In 1937 and 1938 he published a series of articles in Harper's that examined the deteriorating political situation in Europe. In August of 1939, while working on a mystery series for the Saturday Evening Post, Davis was invited by the Columbia Broadcasting System (CBS) to fill in for popular radio broadcaster H. V. Kaltenborn, who had gone to Europe to cover the news. Leaving his mystery serial unfinished, Davis, who had filled in for Kaltenborn briefly during the summer of 1937, stepped in front of the microphone to become a radio news analyst. What had been intended as a temporary assignment soon became Davis's new career.
With the onset of World War II, radio news became increasingly important. Thus, when Nazi Germany invaded Poland just ten days after Davis joined CBS. Davis quickly became popular among listeners who found his commentary insightful. Before long he had an audience of more than 12 million listeners, and CBS responded by offering him a permanent position.
Before long Davis's voice could be heard in mid-morning and during the peak listening hours of early evening. He also frequently anchored CBS's international report, "World News Roundup," and provided occasional 15-minute commentaries on foreign affairs. He continued to contribute written commentary to such publications as Harper's and the Saturday Review.
In March of 1941 CBS sent Davis to England for five weeks. During this time, Davis, often accompanied by Murrow, toured the war-torn city of London and outlying areas, reporting back to the United States what he had seen in nightly broadcasts. He returned to the United States now believing that for the Allies to defeat Hitler, the direct involvement of the United States would be necessary. Davis's broadcasts helped rally support for the war even though the majority of Americans, like Davis himself, had previously wished to remain militarily uninvolved..
During a March 1942 broadcast, Davis, who had consistently complained on air about the chaos of governmental news dissemination, advocated the creation of a government organization that could coordinate the war news. As a result, in June 1942 President Roosevelt established the U.S. Office of War Information (OWI) and named Davis as its director. With a budget reaching nearly $25 million and some 30,000 people on staff, Davis developed a federal news agency that employed the services of writers, editors, advertisers, lawyers, and publicists. The staff also included sociologists, psychologists, playwrights, and poets. With the slogan "This is a people's war, and the people are entitled to know as much as possible about it," Davis began his job at the OWI.
In September of 1945, with the war at an end, the OWI was dissolved and Davis returned to radio as a commentator for the American Broadcasting System (ABC), later becoming a television broadcaster with the ABC network. During the 1940s Davis tried to strike a balance in his understanding of Communist aggression that was feared by much of the American public. Although he condemned Communism and abhorred the Soviet invasion of Czechoslovakia, he understood there to be a difference between external aggression and internal, popular revolution, such as the Chinese communist revolution. Senator Joseph McCarthy of Wisconsin set off a massive, nationwide campaign against Communism with the announcement on February 9, 1950, that he could name 205 Communists within the State Department. Davis felt it his duty to speak out against what became known as McCarthyism. During 1953 he traveled across the United States to advocate for rational thinking, defend freedom of thought, and promote the need for civil liberties.
In 1954 Davis published the bestseller But We Were Born Free, a collection of his speeches and essays. Throughout the book he expounds on the need for optimism, clear-headed thinking, and the courage to stand against those who wished to tear the country apart through intolerance and willful ignorance. But We Were Born Free sold almost 100,000 copies. By the end of 1954 McCarthyism had come to an end after the Army-McCarthy hearings resulted in the denouncement and congressional censorship of McCarthy. In 1955 Davis published his last book, an examination of the threat of nuclear war entitled Two Minutes Till Midnight. In March 1958, Davis suffered a stroke. He died two months later on May 18, 1958, in Washington, D.C.
Married Florence MacMillan, February 5, 1917. Children: Robert Lloyd, Carolyn Anne.