Siegfried Beer is an Austrian historian and secret service specialist. Until his retirement in October 2013, he was an associate professor at the Karl-Franzens University Graz at the Institute of History. He is a lecturer in General Modern History and General Contemporary History.

Beer studied History and English/American Studies at the University of Vienna and at Wesleyan University in Middletown (Connecticut). He habilitated at the University of Graz for general modern and general contemporary history, where he worked as an associate professor. Beer was a Schumpeter Research Professor at Harvard University from 1996-1997. He has been a member of the Vienna Restitution Commission since 1999 and of the Historical Commission for Styria (HLK) since 2004. In 2007 he was Botstiber Visiting Professor at Columbia University, and since 2008 he has headed the Botstiber Institute for Austrian-American Studies (BIAAS) in Media, Pennsylvania. In 2014 he became a member of the European Academy of Sciences and Arts.

His research focuses on international relations in the 19th and 20th centuries, Anglo-American history since 1776, secret services in the 20th century, Austria in the 20th century. He is the director of ACIPSS, the Austrian Center for Intelligence, Propaganda and Security Studies, which he founded in 2004. Since 2007 Siegfried Beer has been editor of the "Journal for Intelligence, Propaganda and Security Studies" (JIPSS).