M. G. Radhakrishnan was born on at Haripad, as the elder son of music composer and Harmonist Malabar Gopalan Nair and Harikatha exponent Kamalakshi Amma. He was the eldest of their three children. He had his college education from the S. D. College, Alappuzha, and took Ganabhooshanam from Swati Tirunal Music Academy. Prominent singer K. J. Yesudas was one of his classmates there. Radhakrishnan worked as a staff and become the senior music composer(grade 1) in Akashvani, Trivandrum.
He made his debut in cinema as a playback singer through “Unniganapathiye” from Kallichellamma (1969). Famous songs as a vocalist include “Sharike Sharike” from Sharashayya, “Pallanayattin Theerathu” from Ningalenne Communist Aakki etc. Debut film as a music director was Thampu (1978). The songs were fairly noticed, however the first notable work by M.G. was Thakara (1980). Songs from this film, Mouname Mouname and Kudayolam Bhoomi won him accolades and fame. The other major works by him include Adwaitham, Devasuram, Manichithrathazhu and Rakkuyilin Rajasadassil. Ananthabhadram was his last work. His younger brother M. G. Sreekumar is a leading playback singer in Malayalam and Tamil cinema and his younger sister K. Omanakutty is a famous carnatic vocalist and academician. He died on July 2, 2010 in a private hospital in Thiruvananthapuram due to liver disease, less than a month short of his 70th birthday. He was later cremated with full state honours at Santhikavadam crematorium in Thaikkad, Thiruvananthapuram.