Hariharan is an Indian playback, bhajan and ghazal singer who predominantly sings in Tamil, Hindi and Telugu languages. He has also sung over 15,000 notable songs in 10 languages including Malayalam, Kannada, Marathi, Sinhala, Bhojpuri, Odia, Bengali, Sanskrit, Gujarati and English. He is an established ghazal singer and one of the pioneers of Indian fusion music.

In 2004, he was honoured with the Padma Shri by the Government of India and is a two-time National Award winner. Hariharan, associating with Leslee Lewis, formed Colonial Cousins, a two-member band. They have cut many private music albums and also scored music for few feature films in Tamil and Hindi. In 2023, Hariharan and late Gulshan Kumar`s Hanuman Chalisa recorded under the label of T-Series crossed the 3-billion views mark on YouTube making it the first devotional song in the world to do so.