Early life and background
Kajol was born in Mumbai to the Mukherjee-Samarth film family of Bengali-Marathi descent. Her mother, Tanuja, is an actress, while her father Shomu Mukherjee was a film director and producer. Shomu died in 2008 after suffering cardiac arrest. Kajol's younger sister, Tanishaa Mukherjee is also an actress. Her maternal aunt was actress Nutan and her maternal grandmother, Shobhna Samarth, and great grandmother, Rattan Bai, were both involved in Hindi cinema. Her paternal uncles, Joy Mukherjee and Deb Mukherjee, are film producers, while her paternal and maternal grandfathers, Sashadhar Mukherjee and Kumarsen Samarth, were filmmakers. Kajol's cousins Rani Mukerji, Sharbani Mukherjee and Mohnish Behl are also Bollywood actors; whereas another cousin of hers, Ayan Mukerji is a director.
Kajol describes herself as being "extremely mischievous" as a child. She added that she was very stubborn and impulsive from a very young age. Her parents separated when she was young; but according to Tanuja, Kajol was not affected by the split as "we never argued in front of [her]". In the absence of her mother, Kajol was looked after by her maternal grandmother, who "never let me feel that my mother was away and working". According to Kajol, her mother inculcated a sense of independence in her at a very young age. Growing up between two separate cultures, she inherited her "Maharashtrian pragmatism" from her mother and her "Bengali temperament" from her father.
Kajol studied at the St Joseph Convent boarding school in Panchgani. Apart from her studies, she participated in extra-curricular activities, such as dancing. It was in school that she began to form an active interest in reading fiction, as it helped her "through the bad moments" in her life. At the age of sixteen, she began work on Rahul Rawail's film Bekhudi, which according to her was a "big dose of luck". She initially intended to return to school after shooting for the film during her summer vacations. However, she eventually dropped out of school to pursue a full-time career in film. On not completing her education, she quoted, "I don't think I am any less well-rounded because I didn't complete school".