Dr. Conquest was a fellow of the Royal Society of Literature, British Academy, British Interplanetary Society, and American Academy of Arts and Sciences; and a member of the Society for the Promotion of Roman Studies. He had been a research fellow at the London School of Economics, fellow of the Columbia University Russian Institute and the Woodrow Wilson International Center for Scholars, distinguished visiting scholar at the Heritage Foundation, and research associate of Harvard University's Ukrainian Research Institute.

He is the author of the twenty-one books on Soviet history, politics and international affairs, including V. I. Lenin , Reflections on a Ravaged Century, The Great Terror: A Reassessment, Harvest of Sorrows: Soviet Collectivization and the Terror-Famine, Stalin: Breaker of Nations, and Stalin and the Kirov Murder. He has also been Literary Editor of the London Spectator, has brought out seven volumes of poetry and one of literary criticism, edited the seminal New Lines anthologies (1955–63), and published a verse translation of Aleksandr Solzhenitsyn's epic Prussian Nights (1977). He is also the author of the science fiction novel, A World of Difference (1955), and he is joint author (with Kingsley Amis) of another novel, The Egyptologists (1965). In 1997, he received the American Academy of Arts and Letters' Michael Braude Award for Light Verse.

He was the recipient of the Alexis de Tocqueville Award, Presidential Medal of Freedom (2005), and Poland's Commander's Cross of the Order of Merit (2009), and in 1996 he was named a Companion of the Order of St. Michael and St. George.