Joan Derk, Baron van der Capellen tot den Pol (November 2, 1741, Tiel – June 6, 1784, Zwolle) is a Dutch nobleman who plays a prominent role in the revolutionary events that preceded the formation of the Batavian Republic.
As a member of the Patriots and inspired by the American Revolution, he writes the noted pamphlet Aan het Volk van Nederland ("To the People of the Netherlands"), pleading for a more liberal society and the end of the Stadtholder regime, which has been marked by corruption and nepotism.
He is also an ardent supporter of the legal recognition of the recently created United States of America.