Francis Wayland Ayer (February 4, 1848 – March 5, 1923) was an American advertising businessman.
Ayer was born to Nathaniel Wheeler Ayer and Joanna B. Wheeler in Lee, Massachusetts, though he was raised in western New York. Ayer taught in district schools and spent one year studying at the University of Rochester before moving to Philadelphia. There he was hired by a religious newspaper for the position of an advertising solicitor, but by 1867 he and his father founded their own company, N. W. Ayer & Son. Besides themselves, they began with only a bookkeeper and US$25.
In 1873 his father Nathaniel died, leaving him to become the senior partner of the company. Two years later he married his first wife, Rhandera Gilman. That same year he introduced the "open contract".
In 1914 his first wife died, and five years later he remarried Martha K. Lawson.