Shankar trained in Carnatic music and Hindustani classical music from a very young age. He entered the singing arena when Bollywood already had two established singers Udit Narayan and Kumar Sanu at their peak. He released his debut album Breathless in 1998. The title track breathless became a huge hit and made him an overnight star. His song Suno Gaur Se Duniya Walo from the unreleased film Dus was among his initial hit songs. He sang songs similar to Breathless in some films and advertisements and became one of the sought after singer in the country. He reached the pinnacle of his career after his collaboration with legendary composer A.R. Rahman in Tamil movies. He also won National Award for the Tamil song Kandukondain Kandukondain.
He collaborated with Ehsaan Noorani and Loy Mendonsa and together the trios were referred as Shankar-Ehsaan-Loy. After forming a formidable partnership with Dil Chahta Hain, they never looked back. Some of their well-known compositions include Taare Zameen Par, Kal Ho Na Ho, My Name is Khan, Wake Up Sid and Lakshya among several others.
In his illustrious career, he along with his other twp partners has won National award for music composition of the film Kal Ho Na Ho and as a singer, he has won it not just once but thrice. His contribution to Indian music is immensely massive and is virtually impossible to gather them all.
He along with his friend Sridhar Ranganathan founded the Shankar Mahadevan Academy. Through this academy, he gives tutorials and an innovative way of learning with live teachers in religious chanting, Hindustani classical & Carnatic music, Bollywood songs and Indie music.