Carl Ludwig Willdenow (22 August 1765 – 10 July 1812) was a German botanist, pharmacist, and plant taxonomist.

After studying pharmaceutics at Wieglieb College, Langensalza and in medicine at Halle, he returned to Berlin to work at his father's pharmacy located in the Unter den Linden.

His early interest in botany was kindled by his uncle J. G. Gleditsch and he started a herbarium collection in his teenage years.

He subsequently visited Willdenow without an appointment and found him to be a kindred soul only four years older and in three weeks he became an enthusiastic botanist.

This was contrary to earlier assertions by Eberhard August Wilhelm von Zimmermann that plants were distributed as they had been in the past and that there had been no changes.