Biddu, or Biddu Appaiah (Kannada: ಬಿದ್ದು ಅಪ್ಪಯ್ಯ, Hindi: बिद्दु अप्पय्या) (born 1944), is an Indian-born, England-based music producer, composer, songwriter and singer who produced and composed many hit records worldwide during a career spanning five decades. Considered one of the pioneers of disco, Euro disco, and Indian pop, he has sold millions of records worldwide, and has received Grammy and Ivor Novello awards for his work. He has been ranked at number 34 on NME's "The 50 Greatest Producers Ever" list.

Biddu was born in Bangalore, Karnataka, India. He began his music career in the 1960s, singing as part of a music band in India before moving to England where he would start his career as a producer. He eventually found some success producing a hit song for Japanese band The Tigers in 1969, scoring the soundtrack for 1972 British film Embassy, and producing several early disco songs that would find a niche audience in British northern soul clubs during the early 1970s.