Hemanth was born in a family of musicians at Bangalore, India, his mother Smt. Rathna Sastry is a classical singer and his father Sri Subramanya Sastry is a retired economics professor who is also an ardent music lover. Hemanth nurtured his love towards music from the tender age of four. Since his childhood days he used to accompany his mother while she performed carnatic and light classical shows and he considers his mother as his first Guru.
Hemanth practiced Carnatic classical music under Vidwan Sri R. K. Srikantan and his son Vidwan Sri R.S.Ramakanth and also under Dr. Nagavalli Nagaraj and Sri H. K. Narayana for about a decade.
Hemanth was alleged by his wife priyadarshini for dowry harassment in 2009. In 2013, the allegation was dropped due to lack of evidence.
Hemanth started his film career as a music assistant to the legendary music director Dr. Hamsalekha, who also introduced him to the Kannada cinema. His foray into the film world was made in 2000 for the blockbuster movie Preethse. Hemanth replaced Udit Narayan in his debut song "Preetse Preetse" of movie Preethse composed by his mentor Dr. Hamsalekha. The total number of Kannada songs rendered by him till date exceeds a few thousands.
Hemanth became a popular and prominent playback singer in Kannada cinema since his debuted with super hit and evergreen song "Preetse Preetse" of Kannada cinema. Hemanth rendered his voice to many Kannada cinema heroes, Dr. Shiva Rajkumar, Puneeth Rajkumar, Upendra, Ganesh, Sudeep, Srinagar Kitty, Darshan, Yash to name a few. Hemanth has sung songs in composition of Dr. Hamsalekha, V. Manohar, Gurukiran, Mano Murthy, Arjun Janya, Anoop Seelin, V. Sridhar, V. Harikrishna, Sadhu Kokila, Ricky Kej to name a few.
Hemanth has hosted and performed for innumerable TV musical shows in leading Kannada channels. “Kuhu Kuhu" for Udaya TV, “Gunagaana", "Sa Re Ga Ma Pa” and "Sa Re Ga Ma Pa little champs" for Zee Kannada TV to name a few. He has performed live worldwide, including at Muskat for the show “Gana Lahiri” organized by Kannada Sangha in 2008, at Dubai in 2012 and at Bahrain in 2013.
Hemanth has also sung song in music albums "Life is Beautiful" and "Baa Sangaati" composed by Techies4Kannada and orchestral music from the Czech Republic. He is also featured in "Nee Badalaadare" music album composed by Ricky Kej which has patriotic songs in Kannada.
Partial list of songs sung by Hemanth.
Karnataka State Film Award for Best Male Playback Singer - 2007 for Janapada
Filmfare Award for Best Male Playback Singer – Kannada - 2007 for Kallarali Hoovagi song "Kallarali Hoovaagi"
Karnataka Chitra Rasikara Sangha Awards for Best Singer 2007 for Mungaru Male
Karnataka State Film Award for Best Male Playback Singer - 2006 for Kallarali Hoovagi
Best Playback singer (male) - Exo Asianet Kaveri Film Awards 2001 for Preethse, song "Preethse Preethse"
Best Playback singer (male) - Asianet Suvarna TV ( Star TV ) Award 2001 for Preethse, song "Preethse Preethse"
Best Playback singer (male) - Suprabhatha Award 2001 for Preethse, song "Preethse Preethse"