Robert Sayer (1725 - January 29, 1794) was an important English map publisher and engraver active from the mid to late 18th century. Sayer was born in Sunderland, England, in 1725. He may have clerked as a young man with the Bank of England, but this is unclear. His brother, James Sayer, married Mary Overton, daughter-in-law of John Overton and widow of Philip Overton. Sayer initially worked under Mary Overton, but by December of 1748 was managing the Overton enterprise and gradually took it over, transitioning the plates to his own name. When Thomas Jefferys went bankrupt in 1766, Sayer offered financial assistance to help him stay in business and, in this way, acquired rights to many of the important Jefferys map plates as well as his unpublished research. From about 1774, he began publishing with his apprentice, John Bennett (fl. 1770-1784), as Sayer and Bennett, but the partnership was not formalized until 1777. Bennett retired in 1784 following a mental collapse and the imprint reverted to Robert Sayer. From 1790, Sayer added Robert Laurie and James Whittle to his enterprise, renaming the firm Robert Sayer and Company. Ultimately, Laurie and Whittle partnered to take over his firm. Sayer retired to Bath, where, after a long illness, he died. During most of his career, Sayer was based at 53 Fleet Street, London. His work is particularly significant for its publication of many British maps relating to the American Revolutionary War. Unlike many map makers of his generation, Sayer was a good businessman and left a personal fortune and great estate to his son, James Sayer, who never worked in the publishing business.