Unni Menon is a South Indian film playback singer. He has sung over 500 songs in South Indian languages like Tamil, Telugu and Malayalam. In the early part of his career, he spent many years as a low-profile playback singer. The turning point in his career came when he sang the song Puthu Vellai Mazhai from Mani Ratnam's award winning 1992 Tamil film Roja, composed by A. R. Rahman. He has frequently associated with A. R. Rahman, lending his voice to nearly 25 memorable songs from films like Karuththamma (1994) and Minsaara Kanavu(1997). He has also worked with renowned music composer Ilayaraaja,Shyam, Vidyasagar and Harris Jayaraj.

Unni Menon moved to Chennai (then Madras) where he had a job in the Heavy Vehicles Factory at Avadi. Many of the prominent recording studios of South India were located in Chennai. His interest in music led him to visit these studios regularly and formed acquaintances with many prominent artistes like the singer K. J. Yesudas and composer Ilayaraaja. Soon he had graduated from singing tracks for prominent singers and was becoming a singer sought after by many music directors.

His career got a major boost in 1992 when A. R. Rahman offered him the song Puthu Vellai Mazhai. That song went on to become a huge hit, as were all the other songs from the film and fetched A. R. Rahman the Rajat Kamal for Best Music Director at the National Film Awards. Since then sung many songs which have become big hits.