The Directory of Open Access Repositories (OpenDOAR) 
Authoritative directory of academic open access repositories. Search for a particular repository, or search the entire database of repositories for particular types of resources. Includes texts and media in all disciplines.
Amazon Web Services Public Data Sets
"Public Datasets on AWS provides a centralized repository of public datasets that can be seamlessly integrated into AWS cloud-based applications. AWS is hosting the public datasets at no charge for the community, and like all AWS services, users pay only for the compute and storage they use for their own applications" (home page). Includes data sets for sciences, economics, geography, and general topics.
Data.gov
"The home of the U.S. government's open data. Here you will find data, tools, and resources to conduct research, develop web and mobile applications, design data visualizations, and more" (Home Page).
DataCite
"Locate, identify, and cite research data with the leading global provider of DOI's for research data" (home page). Includes re3data.org, Registry of Research Data Repositories.
Knoema 
Discover the world's free and open data by industry, source, country, or keyword. Explore data using Knoema's World Data Atlas. Knoema includes free daily data visualizations and tutorials that allow you to create your own.
Nature's Recommended Data Repositories
Nature provides a list of open data repositories for scientific research. They also provide suggestions to researchers who would like to submit their data to open repositories.
PLOS Recommended Repositories
The Public Library of Science (PLOS) has identified a set of repositories that are recognized and trusted within their research communities. Includes three data repositories for social sciences as well as STEM fields.
University of Minnesota Discipline-Based Data Archives
Includes excellent guide to managing your research data
Authoritative directory of academic open access repositories. Search for a particular repository, or search the entire database of repositories for particular types of resources. Includes texts and media in all disciplines.
Amazon Web Services Public Data Sets
"Public Datasets on AWS provides a centralized repository of public datasets that can be seamlessly integrated into AWS cloud-based applications. AWS is hosting the public datasets at no charge for the community, and like all AWS services, users pay only for the compute and storage they use for their own applications" (home page). Includes data sets for sciences, economics, geography, and general topics.
Data.gov
"The home of the U.S. government's open data. Here you will find data, tools, and resources to conduct research, develop web and mobile applications, design data visualizations, and more" (Home Page).
DataCite
"Locate, identify, and cite research data with the leading global provider of DOI's for research data" (home page). Includes re3data.org, Registry of Research Data Repositories.
Knoema
Discover the world's free and open data by industry, source, country, or keyword. Explore data using Knoema's World Data Atlas. Knoema includes free daily data visualizations and tutorials that allow you to create your own.
Nature's Recommended Data Repositories
Nature provides a list of open data repositories for scientific research. They also provide suggestions to researchers who would like to submit their data to open repositories.
PLOS Recommended Repositories
The Public Library of Science (PLOS) has identified a set of repositories that are recognized and trusted within their research communities. Includes three data repositories for social sciences as well as STEM fields.
University of Minnesota Discipline-Based Data Archives
Includes excellent guide to managing your research data
Open data is data that can be freely used, re-used and redistributed by anyone - subject only, at most, to the requirement to attribute and sharealike. Open data must meet the following three requirements:
Cited from the Open Data Handbook, a publication of Open Knowledge International.
- Availability and Access: the data must be available as a whole and at no more than a reasonable reproduction cost, preferably by downloading over the internet. The data must also be available in a convenient and modifiable form.
- Re-use and Redistribution: the data must be provided under terms that permit re-use and redistribution including the intermixing with other datasets.
- Universal Participation: everyone must be able to use, re-use and redistribute - there should be no discrimination against fields of endeavour or against persons or groups. For example, ‘non-commercial’ restrictions that would prevent ‘commercial’ use, or restrictions of use for certain purposes (e.g. only in education), are not allowed.
Cited from the Open Data Handbook, a publication of Open Knowledge International.
