ICPSR - the Interuniversity Consortium for Political and Social Research
The world's largest archive of social research data, including U. S. and international studies and polls on all topics. Some noteable surveys include: American Public Opinion and United States Foreign Policy Series, the Eurobarometer Survey Series, Foreign Conflict Behavior, 1950-1968, and too many others to count, let alone list.
Terrorism and Preparedness Data Archive
The TPDRC archives and distributes data collected by government agencies, non-governmental organizations (NGOs), and researchers about the nature of intra- (domestic) and international terrorism incidents, organizations, perpetrators, and victims; governmental and nongovernmental responses to terror, including primary, secondary, and tertiary interventions; and citizen's attitudes towards terrorism, terror incidents, and the response to terror.
Pew Research Center For The People & The Press
The Pew Research Center is an independent American opinion research group that studies attitudes toward the press, politics and public policy issues. They are best known for regular national surveys that measure public attentiveness to major news stories, and for their polling that charts trends in values and fundamental political and social attitudes.
Pew Global Attitudes Project
The Pew Global Attitudes Project is a series of worldwide public opinion surveys that encompasses a broad array of subjects ranging from people's assessments of their own lives to their views about the current state of the world and important issues of the day.
Odum Institute Public Opinion Poll Question Database
The Odum Institute houses the Louis Harris Data Center, the national depository for publicly available survey data collected by Louis Harris and Associates, Inc. More than 1,200 Harris Polls from as early as 1958 are archived at the Center. A few studies cover Canada, including the 1991 Health Care in Three Nations study and the 1991 Five Nations Elderly Survey. Many of the datasets, including the Harris polls, are available for direct download.
Comparative Study of Electoral Systems (CSES)
Participating countries (including Canada) include a common module of survey questions in their post-election studies. The resulting data are deposited along with voting, demographic, district and macro variables. The studies are then merged into a single, free, public dataset for use in comparative study. Complete data files for many of the contributing countries' election studies are also linked from this site.
World Values Survey and European Values Surveys
The series is designed to enable a cross-national comparison of values and norms on a wide variety of topics and to monitor changes in values and attitudes across the globe. Data is currently available for 1981-1984, 1990-1993, 1995-1997, 1999-2004, and 2005-2008.
UNData (formerly the U.N. Common Database)
Data collected by the United Nations - a very comprehensive source of comparitive international statistics, covering demographics, social issues, finance, governance, trade, etc.
Comparative data for OECD countries on government expenditures, health, education systems, population growth, economic output, etc.
Gary King Dataverse
Includes 10 Million Dyadic Events, a database of international conflict events, each coded to the exact day they occur or become known. This site also houses other datasets for quantitative political science research.
International Military Intervention, 1989-2005
Documents military intervention across international boundaries by regular armed forces of independent states). "Military interventions are defined operationally in this collection as the movement of regular troops or forces (airborne, seaborne, shelling, etc.) of one country inside another, in the context of some political issue or dispute"(Pearson and Baumann, 1993).
Data from the Centre for the Study of Civil War
Includes data on armed conflicts, governance, natural resources, ethnic composition and some basic demographic and economic data.