Ephraim Chambers was an English writer and encyclopaedist, who is primarily known for producing the Cyclopaedia, or an Universal Dictionary of Arts and Sciences. Chambers' Cyclopædia is known as the original source material for the French Encyclopédie that started off as a translation of Cyclopædia.

Cyclopædia: or, An Universal Dictionary of Arts and Sciences is a British encyclopedia prepared by Ephraim Chambers and first published in 1728; six more editions appeared between 1728 and 1751 with a Supplement in 1753. The Cyclopædia was one of the first general encyclopedias to be produced in English.