Son of Bengal, Manna Day sahib

During Dey's years at Scottish Church College, he sang to entertain his classmates. He began taking singing lessons from his uncle, Krishna Chandra Dey and Ustad Dabir Khan. During this period, Manna Dey stood first for three consecutive years in three different categories of inter-collegiate singing competitions.

In 1942, Dey accompanied Krishna Chandra Dey on a visit to Bombay. There he started working as an assistant, first under Krishna Chandra Dey, and then under Sachin Dev Burman. Later he assisted other music composers and then started to work independently. While working independently as a music director for various Hindi movies, Manna Dey continued to take musical lessons in Hindustani classical music from Ustad Aman Ali Khan and Ustad Abdul Rahman Khan.

Dey started his career in playback singing with the movie, Tamanna, in 1943. The musical score was by Krishna Chandra Dey and Manna sang a duet with Suraiya. The song was an instant hit. He sang a solo composed by Sachin Dev Burman, Upar Gagan Vishal, in the 1950 movie, Mashal. Its lyrics were written by Kavi Pradeep. In 1952, Dey sang for a Bengali and a Marathi movie with the same name and storyline, Amar Bhupali. This established him as a leading playback singer.

Dey recorded a popular duet, Ketaki Gulab Juhi, with classicist Bhimsen Joshi. With Kishore Kumar, he sang duets of different genres such as, Yeh Dosti Hum Nehi Torenge (Sholay) and Ek Chatur Naar (Padosan). Dey sang with singer/composer, Hemant Kumar (Hemanta Mukherjee), in Bengali movies, and also for some other Bengali composers. He sang a duet, "Ke Prothom Kachhe Esechi", with Lata Mangeshkar in the movie Sankhyabela. He also performed Rabindra Sangeet and has recorded over 3500 songs.

On 18 December 1953, Manna Dey married Sulochana Kumaran from Kerala. They have two daughters: Shuroma, born on 19 October 1956; and Sumita, born on 20 June 1958.

Manna Dey currently lives in Bangalore in the township of Kalyannagar after spending more than fifty years in Mumbai. He also maintains a Calcutta address. He still travels widely in the world to present musical programs.

His Bengali-language autobiography, Jiboner Jalsaghorey, has been published by the renowned Ananda Publisher in the year 2005 which has been translated in English as Memories Come Alive, in Hindi as Yaden Jee Uthi and in Marathi as Jiboner Jalsaghorey.

Jibaner Jalsaghore, a documentary on Dey's life, was released in 2008. Manna Dey Sangeet Academy is developing a complete archive on Manna Dey. In association with Rabindra Bharati University, Kolkata, the Manna Dey Music Archive has been developed in the Sangeet Bhawan.