Alfred Deller (born May 31, 1912, died July 16, 1979) was an English singer, one of the main figures in popularizing the use of the countertenor voice in renaissance and baroque music.
Deller was born in Margate, and as a boy studyied singing with his father. When his voice broke, he continued singing as a countertenor. He concentrated on English baroque and renaissance music by composers such as John Dowland and Henry Purcell. He formed the Deller Consort in 1948, a group dedicated to historically accurate performances of that kind of music.
In 1960, Deller sang the role of Oberon in Benjamin Britten's opera A Midsummer Night's Dream. This was the first role for a countertenor since the baroque period, and Britten wrote it with Deller specifically in mind.