Christian Knaut (August 16, 1656 – April 11, 1716) was a German physician, botanist and librarian born in Halle an der Saale.
He studied medicine at the University of Leipzig, where he had as instructors Gottfried Welsch, Paul Amman, Michael Ettmüller and Johannes Bohn.
Afterwards he returned to Halle, where he served as a librarian and personal physician to Prince Emanuel Lebrecht of Anhalt-Köthen.
As a botanist he published Compendium Botanicum sive Methodus plantarum genuina, in which he provided a classification system for flowering plants based on petal number and arrangement.
Carolus Linnaeus named the plant genus Knautia in honor of Christian and Christoph Knaut.