William Carpenter (25 February 1830 – 1 September 1896) was an English printer and author, and a proponent of the flat Earth hypothesis, active in England and the United States in the nineteenth century.

The 1880 US federal census shows him and his wife Annie with six children aged 11–25 years, whose occupations included milliner, architect, professor of music, and florist.

Carpenter, a printer originally from Greenwich, England, published Theoretical Astronomy Examined and Exposed – Proving the Earth not a Globe in eight parts from 1864 under the name Common Sense.

Rowbotham also produced studies, mostly printed by Carpenter, that purported to show the effects of ships disappearing below the horizon could be explained by the laws of perspective in relation to the human eye.

[6] Some of Carpenter's works found commercial publishers, but many were printed, bound, and sold by himself, at times under the pen-name "Common Sense".