Kajol is the daughter of Tanuja and Shomu Mukherjee and niece of Nutan (Tanuja's sister) and Joy Mukherjee (Shomu Mukherjee's cousin brother). Her real sister is Tanishaa (of Bigg Boss fame) and she is cousins with Monish Bahl (Nutan's son), Rani Mukerji and Ayan Mukerji. She's also the granddaughter of Shobhna Samarth and great granddaughter of Rattan Bai. Like Kajol, her mother, grandmother, sister and great grandmother have been actresses.
Has been paired opposite SRK in 6 films and all went on to become block busters, especially Dilwale Dulhaniya Le Jayenge which broke all box office records, making them the favourite jodi in Bollywood of all time. in fact, Aditya Chopra had trouble filming the scene where Raj (Shah Rukh Khan) jokes with Simran (Kajol) about the previous night. The reason was that every time Shah Rukh Khan would open his shirt, Kajol would not stop laughing. The pictures of the lips on Shah Rukh's chest were drawn by Kajol. Is Karan Johar's lucky mascot and has appeared in cameo roles for his films which include Student of the Year and Kal Ho Naa Ho to name a few.
Courted controversy when she posed with veteran actress Rekha in only a sweater for the cover of a magazine. This did not go down too well with Indian audiences. Made her comeback with the film Fanaa but doesn't consider it to be her comeback. In an interview with The Times of India, she was quoted saying, " Wouldn't call Fanaa my comeback film because I never retired. I had just taken a break." Was offered Rani Mukerji's role in Bombay Talkies . During her husband Ajay Devgn's controversy with YRF, she was quoted saying in Filmfare that Aditya Chopra was once a friend.