William Parker (1821 – April 14, 1891) was an American former slave who escaped from Maryland to Pennsylvania, where he became an abolitionist and anti-slavery activist in Christiana. He was a farmer and led a black self-defense organization. He was notable as a principal figure in the Christiana incident (or riot), 1851, also known as the Christiana Resistance. Edward Gorsuch, a Maryland slaveowner who owned four slaves who had fled over the state border to Parker's farm, was killed and other white men in the party to capture the fugitives were wounded. The events brought national attention to the challenges of enforcing the Fugitive Slave Law of 1850.