Comparative Political Data Set (CPDS) is a collection of political and institutional country-level data from researchers the University of Berne. It consists of annual data for 36 democratic countries.

This site contains data and documentation for a cross-national collection of election studies.

Repository of detailed results of approximately 1600 elections from 130+ countries at a constituency level for lower house national legislative elections. Includes votes received by each candidate/party, total votes cast, number of eligible voters, and seat figures where available.

Covers 180 countries, 1975-2017. Codes 125 variables about executives, governments, and parties.

Results of both national and subnational elections around the world. These data are presented at two levels of analysis, allowing users to quickly identify the results of elections within a country as a whole or within particular constituencies or districts of a country. The data are based on countries' official election results and have been amassed from various government institutions.

From the International Institute for Democracy and Electoral Assistance (IDEA), depicts democratic trends at the country, regional and global levels across a broad range of different attributes of democracy from 1975–2017.
The indices present data for 158 countries around the world and consist of 5 main democracy attributes and 16 subattribute scores per country per year.

The NELDA dataset provides detailed information on all election events from 1960-2006.

The Polity Project examines concomitant qualities of democratic and autocratic authority in governing institutions, rather than discreet and mutually exclusive forms of governance. This perspective envisions a spectrum of governing authority that spans from fully institutionalized autocracies through mixed, or incoherent, authority regimes (termed "anocracies") to fully institutionalized democracies.

The QOG Institute at the University of Gothenburg studies good governance and corruption on a global scale. QoG provides a range of datasets available for free, and data visualization tools.

Varieties of Democracy (V-Dem) provide a multidimensional and disaggregated dataset that reflects the complexity of the concept of democracy as a system of rule that goes beyond the simple presence of elections. The V-Dem project distinguishes between seven high-level principles of democracy: electoral, liberal, participatory, deliberative, egalitarian, majoritarian and consensual, and collects data to measure these principles.