Warner Mifflin (August 21, 1745 – October 16, 1798) was an American abolitionist and an early advocate of reparations for slavery. Born and raised in Virginia, Mifflin established himself as a planter in Delaware in 1769. As a member of the Society of Friends, he was strongly opposed to slavery and became dedicated to assisting slaves who tried to free themselves, to defending free blacks from abuse, as well as encouraging Quakers and others to free their slaves.