An alumnus of Trinity College of Music, London, Stephen Devassy is an Indian music composer, singer, a pianist, working in Malayalam film industry. At an early age of 18, he started his career as a pianist, where he collaborated Johnny Sagarika on the album Ishtamannu, which him earned a good reputation among his peers. He has toured all in India and around the world and has performed at numerous prestigious concerts alongside singer Hariharan and the violin maestro L. Subramanian. He also has his own music band titled Seven and released an album titled Yeh Zindagani. Known for his innovative and diversified style of Indian classical music, he has worked on Sanskrit slokas, mantras and verses from the Upanishads; holy chants on Ganesha, Shiva and Vishnu; Christmas carols and Indian ragas.

He made his music directorial debut with Hariharan Pilla Happy Aanu (2003), which was his maiden venture in Malayalam. Devassy has also done the music arrangement for many films, including Majaa, Thambi, Nammal, Azhagiya Thamizh Magan and Waqt Par Bolna. His other projects include KQ (2013) and Neerali (2018).