National Oceanic and Atmospheric Association:
https://www.ncdc.noaa.gov/data-access
Securities and Exchange Commission – Office of Structured Data:
https://www.sec.gov/structureddata
Census Bureau:
https://data.census.gov/cedsci/
Bureau of Economic Analysis:
https://www.bea.gov/data
COVID-19 data:
https://covidtracking.com/data
https://github.com/CSSEGISandData/COVID-19
Gapminder data:
https://www.gapminder.org/data/​
IPUMS aggregated data:
https://www.ipums.org/
Federal Reserve Economic Data (FRED):
https://fred.stlouisfed.org/
Miscellaneous data providers:
https://challenge.ey.com/challenges
https://www.kdnuggets.com/datasets/index.html
https://www.openml.org/search?type=data
https://archive.ics.uci.edu/