Stephen Mark Kotkin (born February 17, 1959) is an American historian, academic, and author. He is the Kleinheinz Senior Fellow at the Hoover Institution and a senior fellow at the Freeman Spogli Institute for International Studies at Stanford University. For 33 years, Kotkin taught at Princeton University, where he attained the title of John P. Birkelund '52 Professor in History and International Affairs; he took on emeritus status from Princeton University in 2022. He was the director of the Princeton Institute for International and Regional Studies and the co-director of the certificate-granting program in History and the Practice of Diplomacy. He has won a number of awards and fellowships, including the Guggenheim Fellowship, the American Council of Learned Societies, and the National Endowment for the Humanities Fellowship. He is the husband of curator and art historian Soyoung Lee. Kotkin's most prominent book project is his three-volume biography of Joseph Stalin: The first two volumes have been published as Stalin: Paradoxes of Power, 1878–1928 (2014) and Stalin: Waiting for Hitler, 1929–1941 (2017), and the third volume remains to be published.