Hemanta was born in the city of Varanasi, India. His family comes from the village of Baharu, West Bengal. They moved to Kolkata in the early 1900s. Hemanta grew up there and included the Nasiruddin School and later the Partner Institution in the Bhawanipore area. There, he met the long-term theme of Subhas Mukhopadhyay who later became a Bengali poet. During this period, he developed his friendship with famous writer Santosh Kumar Ghosh. At that time, Hemanta wrote short stories, Santosh Kumar wrote poetry and Subhash Mukhopadhyay sang songs.
Coming to the influence of his friend Subhash Mukhopadhyay, Hemant Kumar recorded his first song for All India Radio in 1933. Hemant Kumar got inspiration from Bengali composer Shailesh Das Gupta. In an interview broadcast on television in the 1980s, Hemant Kumar said that he took classical music education from Ustad Fayyaz Khan, but after the death of Ustad he broke this order.