Louis was born on May 8, 1936 in Detroit, Michigan, though his family was from Oklahoma and he was raised in Oklahoma City. As a child Louis attended the First Christian Church in Oklahoma City with his parents, Henry Edward Louis and Bena May Flood, "solidly middle class people who set a strong example of the importance of work, thrift, and family.". Louis admits that he is "less religious," but he describes his philosophy in life with the one-liner made famous by Franklin Roosevelt: "I am a Christian and a Democrat. What more does one need in life?"

Louis attended Classen High School, where he especially enjoyed literature and where he thrived as a member of Classen's orchestra, in which he played the French horn. He later became assistant first horn player in the Oklahoma City Symphony. Louis was also involved in swimming at Classen, and in gymnastics and handball at the local YMCA. Louis's involvement with the YMCA gave him his first experience with segregation in Oklahoma, and he traces his commitment to civil rights to that experience. The YMCA also gave Louis his first opportunity to travel to Europe and England.

Louis entered the University of Oklahoma in 1954 as a Letters Major, an honors program that required one ancient and two modern languages, and combined English, history, and philosophy...the equivalent of a liberal arts education. Louis spent his second year of college in Frieburg and Paris, where he roomed with Hans-Peter Schwartz, today known as one of Germany's leading political scientists and the biographer of Adenauer, and where he befriended Nancy Maginnes, the future wife of Henry Kissinger. Louis's time abroad kindled an interest in African and Middle Eastern nationalism. He spent the summer of 1956 in Egypt and was in Cairo when Gamel Abdel Nasser made his speech nationalizing the Suez Canal. The speech was made from Alexandria, but speakers were wired throughout Cairo, and Louis's Egyptian friends kept him informed of the happenings. Louis spent his last two years of college at the University of Oklahoma, where he graduated Phi Beta Kappa.

With the help of OU's Philip Nolan, Louis applied for a Woodrow Wilson Fellowship, and was admitted to Harvard in 1959. "This was a heady experience," Louis later wrote. He took courses with Stanley Hoffman on France, Merle Fainsod and Adam Ulam on Russia, Franklin Ford on Germany, and David Owen on England. The "best of [his] Harvard education," however, were the classes with Rupert Emerson, who taught nationalism in colonial Africa, and Barrington Moore, who provided introduction to Marx and Marxist analysis -- "an approach so radically different from all others that it was a revelation," Louis later wrote. Above all, Louis benefited from Ernest May, who he regards as having "one of the most fertile and inventive minds of all historians I have known."

After one year at Harvard, Louis decided to transfer to St. Antony's College, University of Oxford. The decision was influenced by Arthur Smithies, the great Australian economist, who told Louis: "If you are really interested in studying Nasser and Africa and all that rot, then you had better go somewhere where they know something about it, which definitely is not Harvard.". Smithies helped Louis get a Marshall Scholarship to Oxford, and he began studies in 1960. Louis studied under the historians Margery Perham, John Andrew Gallagher and A.J.P. Taylor, the last of which Louis describes as a "galvanizing experience." Taylor was "not only the towering radical historian of our time, but also one of the great writers of the English language." Louis's time at Oxford centered on the imperial history seminar headed by Vincent Harlow and later by John Gallagher, at which time imperial history had been reinvigorated by the "Robinson and Gallagher" thesis of informal imperialism that later became the subject of one of Louis's edited books. Louis's doctoral thesis began as a comparative study of German, British, and Belgian coloinal administration in central Africa, and later was narrowed to the study published as Ruanda-Urundi.

After Oxford, Louis went to Yale to teach courses on comparative imperialism, where there existed a strong tradition of research in German colonialism. Yale also marked the beginning of his long and successful career of collaborating on edited volumes, among them (with Prosser Gifford) a series on British and German colonialism in Africa and another on A.J.P. Taylor's view on the origins of the Second World War. "At conference after conference," writes Ronald Robinson, "the circle of Louis' consultants widened with the number of contributors. He made his first major contribution to Imperial history as the grand impresario of symposia.". In 1970 Louis moved to the University of Texas at Austin where he took positions as the Kerr Chair in English History and Culture and Director of the British Studies seminar at the " Harry Ransom Humanities Research Center. His ascension to a full professorship allowed for a flurry of publications, both individual and edited, which laid the foundations for Louis's reputation as one of the foremost imperial historians.

Louis's reputation rests on four other seminal contributions to the field of imperial history, as discussed in Ronald Robinson's 1999 tribute entitled "Roger Louis and the Official Mind of Decolonization." The first was Louis's success in collaborating on edited volumes, most while at Yale. Secondly, in 1976, Louis edited a volume on the "Robinson and Gallagher controversy," which emphasized the main lines of a debate that had become the most important of its day for imperial historians. His introductory essay itself proposed something of a consensus that found wide acceptance among other historians.

"Louis made the third and greatest of his contributions to the unities of imperial historiography in writing the original basic narratives of the post-war Empire," including judicious studies of regions that only informally fell under British control (Iran and the Persian Gulf, for instance). His publications, both in article and book form, discussed the era from 1940 to 1967, most in the context of the Cold War and the rise of American power. His first major book, Imperialism at Bay, 1941-1945, tells the story of the contest between British and American officials over the fate of empire in the post-war world. Louis's second and most famous book, The British Empire in the Middle East, 1945-1951, traces the six critical years of Attlee's Labour Government after the war, during which time the British were able to uphold their informal influence in the Middle East with the backing of the United States government, which shifted towards support of the British Empire to create a bulwark against communist advance. These two books contain themes that later became the subject of full-length books edited by Louis. One, with Robert Stookey, covered the Zionist take-over in Palestine under Truman's sponsorship in 1948; another, with James Bill, revisited Musaddiq's nationalization of Iranian oil in 1951; yet another, with Robert Fernea, studied the Iraqi revolution of 1958. More could be added. The general thrust of these contributions was to provide historians with some of the earliest histories of post-war British imperialism, written from the perspective of the "official mind."

The final contribution made by Louis (the fourth one discussed by Robinson has been omitted here because it is a book that exists only in draft) involves what Robinson calls "a symposia to end all symposia." The Oxford History of the British Empire, published initially in five volumes, brought together over six scores of historians in covering four centuries of British imperialism. Multiple reviewers in top academic journals have lauded the series as one of the great achievements of the age. One reviewer, the historian D.A. Low, wrote that, "all in all, these five volumes constitute an extraordinary achievement which has brought Roger Louis's dauntingly formidable editorial skills to their apogee... He has brought the whole enterprise to a conclusion all in one go and in an astonishingly short period of time. Those of us who have organized similar (if very much more modest) ventures can only mop our brows in amazement." The project was funded by the Rhodes Trust and the National Endowment for the Humanities in Washington, D.C. Louis served as Editor-in-Chief of the series, co-editor of the twentieth century volume (with Judith Brown), and author of a historiographic introduction to the fifth volume entitled "Historiography." Some British scholars expressed skepticism publicly when a presumably anti-colonial and "politically correct" American from Texas emerged as the editor-in-chief, but these criticisms were later withdrawn when it became evident that Louis had carried through the series with his usual degree of impartiality.

In all of his work, Louis's style has remained unapologetically empirical with rigorous fidelity to evidence. He prefers the "art of the historian" to the social science approach - the pen portraits that capture fascinating characters, the panorama of official perceptions and misconceptions, narrative over theoretical arguments, and clear, precise writing.

During his time as President of the American Historical Association, Louis wrote an essay entitled " Historians I Have Known," which discusses at length the historians who had the most profound impact on his own scholarship. Louis spends the majority of the essay discussing a handful of Oxford historians, each of which, in their own way, are among the most prominent and influential scholars of their generation: A.J.P. Taylor, Margery Perham, Ronald Robinson, John Gallagher, and Max Beloff. Other influences include Barrington Moore, Jr., Ernest May, and Arthur Smithies - all of Harvard - and Vincent Harlow, Roger Owen, Christopher Platt, Sarvepalli Gopal, and Albert Hourani, all of Oxford.

Louis's scholarship is also influenced by J. C. Hurewitz, a prominent scholar of Israel and Palestine. In the preface to his highly regarded book, The British Empire in the Middle East, 1945-1951, (Clarendon, 1984) Louis stated that “my views on Arab nationalism and Zionism, and on the United States and the Middle East, have been influenced by the sensitive and dead-on-the-mark observations of J. C. Hurewitz.”

Please note that a number of the following titles refer to recently revised versions of these articles as published in Louis's volume of collected essays: Ends of British Imperialism

• "The United States and the African Peace Settlement of 1919: The Pilgrimage of George Louis Beer" (Journal of African History, 1963)
• "Roger Casement and the Congo" (Journal of African History, 1964)
• "E.D. Morel and the Triumph of the Congo Reform Association" (Boston University Papers on Africa, 1966)
• "Australia and the German Colonies in the Pacific During the First World War" (Journal of Modern History, 1966)
• "The Repartition of Africa During the First World War" (American Historical Review, 1966)
• "The Scramble for Africa: Sir Percy Anderson's Grand Strategy" (English Historical Review, 1966)
• "The Beginning of the Mandates System of the League of Nations" (International Organization, 1969)
• "The Berlin Congo Conference and the (Non-) Partition of Africa, 1884-85" (France and Britain in Africa, 1971)
• "Robinson and Gallagher and Their Critics" (The Robinson and Gallagher Controversy, 1976)
• "The Road to the Fall of Singapore, 1942: British Imperialism in East Asia in the 1930s" (The Fascist Challenge and the Policy of Appeasement, 1983)
• "American Anti-Colonialism, Suez, and the Special Relationship" (International Affairs, 1985)
• "The Partitions of India and Palestine" (Warfare, Diplomacy, and Politics: Essays in Honour of A.J.P. Taylor, 1986)
• "The End of the Palestine Mandate" (The End of the Palestine Mandate, 1986)
• "A Prime Donna with Honour: Eden and Suez" (Times Literary Supplement, 31 October 1986)
• "Taking the Plunge Into Indian Independence" (Times Literary Supplement, 28 August 1987)
• "Libya: The Creation of a Client State" (Decolonization and African Independence: The Transfers of Power, 1960-1980, 1988)
• "The Governing Intellect: L.S. Amery, the British Empire, and Indian Independence" (Times Literary Supplement, 26 August 1988)
• "Taxing Transfers of Power in Africa" (Times Literary Supplement, 10 February 1989)
• "An American Volcano in the Middle East: John Foster Dulles and the Suez Crisis" (John Foster Dulles and the Diplomacy of the Cold War, 1990)
• "The Origins of the Iraqi Revolution" (The Iraqi Revolution of 1958, 1991)
• "The Coming of Independence in the Sudan" (Margery Perham and British Rule in Africa, 1991)
• "Prelude to Suez: Churchill and Egypt" (Churchill: A Major New Assessment of His Life in Peace and War, 1993)
• (with Ronald Robinson) "The Imperialism of Decolonization" (Journal of Imperial and Commonwealth History, 1994)
• "Hong Kong: The Critical Phase, 1945-49" (American Historical Review, 1997)
• "The Colonial Empires in the Late Nineteenth and Early Twentieth Centuries" (Oxford History of the Twentieth Century, 1998)
• "The Historiography of the British Empire" (Oxford History of the British Empire, Vol. 5, 1999)
• "The Middle East Crisis of 1958" (A Revolutionary Year: The Middle East in 1958, 2002)
• "The Dissolution of the British Empire in the Era of Vietnam" (American Historical Review, 2002)
• "The Withdrawal from the Gulf" (Journal of Imperial and Commonwealth History, 2003)
• "Musaddiq, Oil, and the Dilemmas of British Imperialism" (Ends of British Imperialism, 2006. Updated from earlier essay in Mohammad Mosaddeq and the 1953 Coup in Iran, 2004)
• "The Pax Americana: Sir Keith Hancock, the British Empire, and American Expansion" (English Historical Review, 2005)
• "Suez and Decolonization: Scrambling out of Africa and Asia" (Ends of British Imperialism, 2006)
• "The British and the French Colonial Empire: Trusteeship and Self-Interest" (Ends of British Imperialism, 2006)
• "The United Nations and the Suez Crisis: British Ambivalence Towards the Pope on the East River (Ends of British Imperialism, 2006)
• "Public Enemy Number One: Britain and the United Nations in the Aftermath of Suez" (The British Empire in the 1950s: Retreat or Revival?, 2006)