The Ki Database (or Ki DB) is a public domain database of published binding affinities (Ki) of drugs and chemical compounds for receptors, neurotransmitter transporters, ion channels, and enzymes. The resource is maintained by the University of North Carolina at Chapel Hill and is funded by the NIMH Psychoactive Drug Screening Program and by a gift from the Heffter Research Institute. As of April 2010[update], the database had data for 7 449 compounds at 738 different receptors and, as of 27 April 2018[update], 67 696 Ki values.

The Ki database has data useful for both chemical biology and chemogenetics.