Diederich von Schlechtendal (27 November 1794 - 12 October 1866) was a German botanist born in Xanten. He was Professor of Botany and Director of the Botanical Gardens at the Martin Luther University of Halle-Wittenberg from 1833 until his death in 1866, and Editor of the botanical journal Linnaea.
His most important work was in describing the then largely unknown Flora of Mexico, carried out in conjunction with Adelbert von Chamisso, and based on specimens collected by Christian Julius Wilhelm Schiede and Ferdinand Deppe between 1824-1829.
The standard botanical abbreviation Schltdl. is applied to species he described.