Samuel Beazley (1786–1851) was an English architect, novelist, and playwright. He became the leading theatre architect of his time and the first notable English expert in that field.
After fighting in the Peninsular War, Beazley returned to London and quickly became a successful architect. He combined this with writing more than a hundred theatre works, generally in a comic style. He is best remembered as a theatre architect, with two major London theatres of his still surviving, together with the well-known façade of another, but he was also an important figure in railway architecture, with many commissions in the south east of England.
Beazley's other activities included translating opera libretti into English, and writing novels and non-fictional works on architecture. He was also a participant in the Berners Street hoax.