Sonali was born in the Marathi-speaking Kulkarni family in Pune, Maharashtra, India. Her dad is an Engineer, and she has two brothers, Sandeep and Sandesh.
Even she was a child her passion was acting, and got her chance to act during the Ganesh Mahotsav celebrations. She was enrolled in the Abhinav Vidhyalaya in Pune, and after completing schooling attended Ferguson College, where she majored in Political Science and got a scholarship in Marathi literature. She used to speak Hindi, Marathi and English fluently, but since then also picked-up Gujarati, Italian, and Tamil.
After attending a workshop by Satyadev Dubey she and Sandesh formed a theater group and called it 'Samanvay'.
She first made her appearance on the tinsel screen in a Tamil movie titled 'Cheluvi', and thereafter has appeared in a total of 32 movies, including one in Italian titled 'Fuoco Si Di Me'.
Apart from acting, she is also an Editor with 'Viva', a supplement of 'Loksatta', and pens a weekly column called 'So Kool'.