Eurostat
Eurostat is the agency within the European Union responsible for statistical information about the continent. It gathers data from national statistical offices and standardises it into comparable series covering the economy, population, environment, agriculture, energy, trade, and society.
The full catalogue is browsable online and reachable through an API, with bulk downloads for larger extracts. Reuse is authorised under Commission Decision 2011/833/EU, which permits reuse for both commercial and non-commercial purposes as long as you acknowledge the source.
Related sources
IMF Data
A gateway to the IMF's global economic data, giving streamlined access to macroeconomic and financial statistics. Includes International Financial Statistics covering balance of payments, interest rates, national accounts, prices, production, trade, and population for more than 200 countries.
OECD Data
Reports, data, and publications on the economic, environmental, and social conditions in hundreds of countries. Includes International Development Statistics covering aid volume, origin, and types, plus the Creditor Reporting System with detailed information on individual aid activities.
Our World in Data
Research and interactive visualisations on global problems, built by aggregating and harmonising data from official sources. Every chart can be downloaded as a ZIP containing a CSV file, JSON metadata, and a README, and the underlying data is available programmatically via an API. Full provenance is documented for every dataset.
SDMX (Statistical Data and Metadata Exchange)
An open standard for exchanging statistical data and metadata electronically, developed jointly by the BIS, ECB, Eurostat, IMF, OECD, UN, and World Bank. Not a dataset itself but the interchange format many statistical agencies use to publish their figures.