Sowmya was born in a Kannada speaking family to veteran singer B. K. Sumitra and Sudhakar in Bangalore, Karnataka, India. Sowmya has a brother named Sunil Raoh, who is an actor in the Kannada film industry. Her mother is popular playback and devotional singer in Kannada. As a child, Sowmya would accompany her mother to the studios for recording. She then slowly graduated to become a child singer. Sowmya's father worked in Reserve Bank of India.
Sowmya started singing at the age of seven. She took a break from singing while she was in school as she thought that would affect her studies. After a period of five to six years, she gradually turned her attention towards singing by learning Carnatic music. However, she ended up becoming a voice actor before venturing into films. She claims that, "I wanted to train for singing for heroines, not children".