English dramatist of pioneer importance in whose domestic tragedy The London Merchant: or, the History of George Barnwell (1731) members of the middle class replaced the customary aristocratic or royal heroes. The play greatly influenced the rise of bourgeois drama in Germany and France, as well as in England.

Lillo was reputedly the son of a Dutch jeweler, and his first piece was a ballad opera (produced in 1730). Inspired by the Elizabethan drama of passion (e.g., the anonymous A Yorkshire Tragedy), The London Merchant tells of a London apprentice who thrice robs his master and murders his uncle. Finally penitent, he is nonetheless executed. The story was based on an old ballad. Denis Diderot wrote his play Le Fils naturel (1757) in imitation of it.