This source is not good for in-depth statistics, but is excellent if you need basic data about a country - population, literacy rate, birth rate, etc.

Eurostat serves as the statistical office of the European Union and its member countries.

Part of the Federal Reserve Bank of St. Louis' portal for economic information, use FRED to download, graph, and track from 290,000 U.S. and international time series from 80 sources.

A list compiled by the U.S. Census Bureau.

This site contains information on health indicators, both for the Americas as a whole and for individual countries.

A portal that allows you to search across several UN statistical databases at once.

"Global and internationally comparable statistics on education, science, technology, culture, and communication."

Free and open access to data about development in countries around the globe.