Data Catalogues

Data catalogues assemble the data available in e-infrastructures related to a certain research field and/or its network. In general, the same data can be found in data registers, but it is often easier to search the disciplinary data catalogue. At the same time one has to investigate, what resources are included in the catalogue and what may be left out.

CESSDA is a Consortium of European Social Science Data Archives and  CESSDA Data Catalogue aggregates social science data from service providers in 20 European countries.
Watch the video about data search in the catalogue:

CLARIN ERIC (Common Language Resources and Technology Infrastructure of European Research Infrastructure Consortium) is a research infrastructure that was initiated from the vision that all digital language resources and tools from all over Europe and beyond are accessible through the online environment for the support of researchers in the humanities and social sciences.
The register of CLARIN language resources is  Virtual Language Observatory (VLO).

Some more examples: 

COVID-19 Data Portal. The portal enables to upload COVID-19 related research data and open access to data. 

OpenML (Open Machine Learning) is for ML data and algorithms.

10 Free GIS Data Sources: Best Global Raster and Vector Datasets.