Vidya Balan as Shakuntala Devi

Sanya Malhotra as Anupama Banerjee

Jisshu Sengupta as Paritosh Banerji

Amit Sadh as Ajay Abhaya Kumar

Luca Calvani as Javier

Sheeba Chaddha as Tarabai

Prakash Belawadi as Shakuntala's Father

Ipshita Chakraborty Singh as Shakuntala's Mother

Ahan Nirban as Srinivas

Chahat Tejwani as Young Anu

Nisha Aaliya as Bookshop Interviewer

Max Dowler as BBC Host

Phillip Roy as Mr. Stevens - Shakuntala's lawyer

Alex Bartram as Edward

Purnendu Bhattacharya as Ajay's Father

Neil Bhoopalam as Dheeraj

Ian Bailley as Mediator

Jon Wennington as Mathematician (uncredited)