All The Datasets Machine Learning UCI Machine Learning Dataset Repository Machine Learning Dataset Repository Deep Learning Deep Learning Datasets for benchmarking deep learning algorithms Clean Sample Data (for Learning New Techniques) Scikit-learn sample datasets Statsmodels datasets Networks Stanford Network Analysis Project Raw Dataz The Guardian / Datasets Qandl provides a lot of interesting data with a clean API. Time Series Data Library USA Congressional Voting Records Voteview Datasets Sources NIPS Feature Selection Curated Lists of Datasets @hmason's curated dataset list bit.ly