William Dillwyn (1743, Philadelphia – 28 September 1824) was a British American-born Quaker of Welsh descent,[1] active in the abolitionist movement in colonial America and after 1774, Great Britain.[2] He was one of the twelve committee members of the Society for Effecting the Abolition of the Slave Trade when it was formed in 1787.[3]
William was the son of John Dillwyn and Susanna Painter. He attended the Friends' English School of Philadelphia where he was taught by Anthony Benezet.[2] His elder brother was George Dillwyn (1738-1820), the quaker minister.