Alliance Treaty Obligations and Provisions Project (ATOP)--The ATOP project "provides data regarding the content of military alliance agreements signed by all countries of the world between 1815 and 2003," such as the obligations created by the alliances, the conditions under which the alliances come into effect, and the processes by which they can be terminated. ATOP data are also accessible via Brett Ashley Leeds' Dataverse.
Cingranelli and Richards (CIRI) Human Rights Dataset--The CIRI Human Rights Dataset contains data on government practices with regard to human rights, including variables on torture, religious freedom, "disappearances," and workers' rights. The data cover the years 1981-2010. While registration is required to access the data, the registration is free.
Climate Change and African Political Stability (CCAPS)--The CCAPS project, which is hosted by the Strauss Center for International Security and Law at UT-Austin, is devoted to the study of the relationship between climate change and international/internal stability on the African continent. The project has produced various data collections such as the Social Conflict Analysis Database (SCAD), which provides event-level data on riots, coups, strikes, and other instances of social unrest, and the Armed Conflict Location and Event Dataset (ACLED), which provides event-level data on various types of armed conflict.
Cline Center Historical Phoenix Event Data--The Cline Center for Advanced Social Research at the University of Illinois has assembled that cover "the period 1945-2015 and includes several million events extracted from 14 million news stories." The data are coded for variable such as the nature and location of the event, the type of government response, and the number of fatalities involved. For post-2015 events data, see the Phoenix Real Time Event Data.
Computational Event Data System--The Computational Event Data System "uses automated coding of English-language news reports to generate political event data focusing on the Middle East, Balkans, and West Africa. These data are used in statistical early warning models to predict political change." The project's data collections consist of coded data on individual political events, including incidents of political violence. NOTE - events data files can be very large and often require some proficiency with database applications or statistical software.
Correlates of War (COW) Project--Penn State's Correlates of War project hosts many popular datasets related to inter- and intra-state conflict. The data cover topics such as Militarized International Disputes (MIDs), countries' material capabilities, alliance memberships, IGO memberships, trade flows, and geographic continuity.
Dynamic Analysis of Dispute Management (DADM) Project--The DADM Project focuses on interventions by third parties (states, international organizations, non-governmental organizations) in instances of internal political conflicts. As part of that work, it distributes data on peacekeeping missions for intra-state conflicts.
FIRST-SIPRI Databases--Facts on International Trends (FIRST) and SIPRI (the Stockholm International Peace Research Institute) have compiled a collection of databases, with a focus on conflict and the arms trade - military expenditures, arms transfers and trade, and peacekeeping missions.
International Crisis Behavior (ICB) Project--The ICB data attemp to measure the dynamics of international crises and the behavior of states in them - the nature and intensity and duration of crises, the traits of states involved in them, and the systemic context in which they occur.
Integrated Network for Societal Conflict Research (INSCR)--The Center for Systemic Peace's Integrated Network for Societal Conflict Research provides access to multiple data collections on political violence and conflict, covering topics such as displaced populations, large-scale violence, acts of terrorism, and political instability in the form of coups and state failures. The INSCR is also the home for the Polity IV data on regime types.
Paul Hensel's International Relations Data Page--This site is run by a professor at the University of North Texas and is a good source for data on international conflicts, economic relations, international organizations, and general political data.
International Interactions Dataverse--International Interactions is a major journal in the field of Political Science, with a focus on conflict and political economy. This Dataverse provides access to replication datasets from articles published in the journal.
International Studies Quarterly Dataverse--International Studies Quarterly is one of the premiere journals for the study of conflict and political violence. This Dataverse provides access to replication datasets from articles published in the journal.
Issue Correlates of War (ICOW) Project Data Archive--The ICOW Project focuses on collecting data related to contentious issues in international policies, such as claims over territory and water bodies, colonial histories, and affilations of ethnic groups.
Minorities at Risk (MAR) Project--The MAR Project is affiliated with the Integrated Network for Societal Conflict Research (INSCR) and the Center for International Development and Conflict Management (CIDCM at the University of Maryland. The project tracks the status of nearly 300 "politically-active communal groups" and the MAR data are used extensively by scholars of ethnic conflict. See https://cidcm.umd.edu/research/minorities-risk-project for updated work on the MAR project.
National Consortium for the Study of Terrorism and Responses to Terrorism (START) Data Collections--The National Consortium for the Study of Terrorism and Responses to Terrorism (START), which is funded in part by the Department of Homeland Security, is devoted to " utilizing state-of-the-art theories, methods, and data from the social and behavioral sciences to improve the understanding of the origins, dynamics, and social and psychological impacts of terrorism." As part of its work, it has assembled data collections on topics such as individual terrorist events, the organizational behavior of ethnic groups in the Middle East and North Africa, profiles of individual perpetrators of terrorist events in the United States, public opinion in Muslim-majority countries, and profiles of individual terrorist organizations. START's Global Terrorism Database is an especially commonly-used data source. START's data collections are available via the START Terrorism Archive Dataverse.
Peace Research Institute Oslo (PRIO)--PRIO "conducts research on the conditions for peaceful relations between states, groups and people." As part of that mission, it collects and distributes a wide range of data as part of its research, including replication datasets from PRIO projects, replication datasets for articles published in the Journal of Peace Research, data on trade in small arms, and othe topics.
Political Terror Scale (PTS)--Mark Gibney at UNC-Asheville has created a 5-point "political terror scale" that codes countries on human-rights conditions and the rule of law, based on reports from Amnesty International and the U.S. State Department. The data cover the years 1976-2014 and are available for downloading.
Quality of Government (QOG) Institute--The QOG Institute is hosted by members of the Department of Political Science at Göteborg University in Sweden and is devoted to "the causes, consequences and nature of 'good governance.'" The Institute has created four collections of data on governance: a broad collection of governance indicators that is global in coverage; a more narrow collection that focuses on social policy in wealthier countries; data from expert surveys on politicization and professionalization of public administration in individual countries, and a new data collection on perceptions of corruption in individual regions within EU members. The data are compiled from multiple sources, including the Polity IV Project, the Cingarelli-Richards Human Rights Data, Transparency International, Freedom House, various international organizations, and datasets produced by various academics. The QoG data are available in SPSS, Stata, and comma-delimited (.csv) formats.
United Nations General Assembly Votes--This site, which is maintained by Erik Voeten at Georgetown, contains data for votes on UN General Assembly resolutions. The data also include estimates of states' foreign policy preferences modeled from the voting data.
The Uppsala Conflict Data Program (UCDP)--The Uppsala Conflict Data Program is run by scholars at Uppsala University in Sweden. Their catalog is a very comprehensive introduction to datasets and other resources pertaining to international and internal conflict. The UCDP also hosts a variety of data collections on political violence, primarily focusing on inter-state conflicts, intra-state conflicts, and terrorism. Among its collections are geo-referenced data on individual events of political violence. The program's various collections of data are freely available to download. See https://www.prio.org/Data/Armed-Conflict/UCDP-PRIO/ for earlier versions of the data.