Tayloe was born September 2, or September 13, 1770. the son of John Tayloe II and Rebecca (née Plater) Tayloe, herself from a long-established Maryland gentry family. Her brother was George Plater and brother-in-law was Edward Lloyd III. His paternal grandfather was Col. John Tayloe I of the Old House; and great grandfather was Col William Tayloe, the nephew of the original settler Col William Tayloe of Kingsmill Plantation, husband of Elizabeth Kingsmill, daughter of Richard Kingsmill of the Virginia Company.
