Kareena Kapoor was born on 21 September 1980 in Bombay. She is the younger daughter of actor Randhir Kapoor and Babita, her elder sister Karisma is also an actress. She is the paternal granddaughter of actor and filmmaker Raj Kapoor, maternal granddaughter of actor Hari Shivdasani, and niece of actor Rishi Kapoor. Her birth name was Siddhima given by Raj Kapoor. Her name "Kareena" was derived from the book Anna Karenina by Leo Tolstoy. She attended Jamnabai Narsee School in Mumbai, Welham Girls' School in Dehradun, Mithibai College in Vile Parle (Mumbai) and Harvard Summer School in the United States. She began training at an acting institute in Mumbai mentored by Kishore Namit Kapoor, a member of the Film and Television Institute of India (FTII). On 16 October 2012, Kapoor married actor Saif Ali Khan in a private ceremony in Bandra, Mumbai. On 20 December 2016, she gave birth to her son, Taimur Ali Khan Pataudi, at Breach Candy Hospital in Mumbai.
She debuted in 2000 alongside Abhishek Bachchan in J. P. Dutta's war drama Refugee and won Filmfare Award for Best Female Debut. Kareena’s Kambakkht Ishq, opposite Akshay Kumar, was the first Indian film to be shot at Universal Studios and featured cameo appearances by Hollywood actors.
Alongside her acting work, Kapoor has established a career as a designer and an author. In 2008, during her five-year association with the retail chain Globus, Kapoor became the first Indian actress to launch her own line of clothing for women. In 2009, Kapoor collaborated with nutritionist Rujuta Diwekar on Don't Lose Your Mind, Lose Your Weight, a book which focused on the principles of healthy eating habits. In February 2013, Kapoor released her autobiographical memoir: The Style Diary of a Bollywood Diva. Co-authored alongside Rochelle Pinto, it became the first book to be launched under the Shobhaa De imprint of Penguin Books.
In 2010, Kapoor adopted the village of Chanderi in Madhya Pradesh as part of NDTV's Greenathon Campaign, to provide the village with a regular supply of electricity. In January 2014, Kapoor began working with UNICEF to advocate the education of girls and increase quality based education in India.