Brill may refer to:

• Brielle (sometimes "Den Briel"), a town in the western Netherlands
• Brill, Buckinghamshire, a village in England
• Brill, Cornwall, a small village to the west of Constantine, Cornwall, UK
• Brill, Wisconsin, an unincorporated community, US
• Brill, Wuppertal, a quarter and town district, Germany

• Brill brothers (Mervall and Descant), fictional characters from the Artemis Fowl book series
• Brill (Elfquest), a fictional character in the comic Elfquest

• Brill tagger, an algorithm in artificial intelligence to detect grammatical structures
• Brill–Noether theory, a theory of algebraic geometry
• Brill–Zinsser disease, a type of epidemic typhus which recurs in someone after a long period of dormancy

• Brill Publishers, a Dutch international academic publisher
• Brill Tramway, a former branch line of the Metropolitan Railway from Quainton Road to Brill
• J. G. Brill Company, a defunct manufacturer of streetcars in North America
• USS Brill (SS-330), a World War II era American Balao class submarine

• Brill (fish), a type of flatfish
• Brill (surname), for people who bear the family name Brill
• Brill Building, a New York City building notable for its influential music industry tenants

• Bril, a surname
• Bril (disambiguation)
• Brühl (disambiguation)
• Brüll, a surname