Donald Dexter Van Slyke (March 29, 1883 – May 4, 1971) was a renowned Dutch American biochemist.
His achievements included the publication of 317 journal articles and 5 books, as well as numerous awards, among them the National Medal of Science and the first AMA Scientific Achievement Award.
A non-SI unit of measurement for buffering activity, the slyke, is named after him, as is the Van Slyke determination, a test of amino acids.