Mahathi is a Carnatic musician and playback singer for film songs in several Indian languages.
Mahathi was born in Chennai to a family of Carnatic musicians. Her maternal great grandfather, Pazhamaneri Swaminatha Iyer, was a Carnatic vocalist and recipient of the Sangeetha Kalanidhi title. Her mother, Vasanthi Sekhar, was a flautist, while her father, Thiruvaiyaru Sekar was a Carnatic vocalist and disciple of M. Balamuralikrishna.
Mahathi moved to Kerala as a toddler, and did her schooling Hari Sri Vidya Nidhi School, Trichur and Sacred Heart Convent, Cochin. She graduated in Chennai from Meenakshi College, Kodambakkam with English literature as her main stream.