Kapoor is the daughter of Anil Kapoor and Sunita Kapoor, and the granddaughter of filmmaker Surinder Kapoor She is the niece of producer Boney Kapoor, actress Sridevi, actor Sanjay Kapoor and producer Sandeep Marwah. Kapoor is the eldest of three children; the others are sister Rhea and brother Harshvardhan.
She went to school in Mumbai at the Arya Vidya Mandir school in Juhu and then enrolled in the United World College of South East Asia to do her International Baccalaureate. She is fluent in English, Hindi and Punjabi, and has received training in classical Indian and Latin dance forms. Kapoor also studied at the University of East London and is categorized as a notable alumni.
Before starting her career off as an actress, Kapoor worked as an assistant under Sanjay Leela Bhansali, and assisted him during the making of his film, Black (2005). She made her acting debut alongside newcomer Ranbir Kapoor in Bhansali's Saawariya (2007), which failed to do well at the box office. Her performance was opened to good reviews by most critics.
In 2009, Kapoor appeared in Rakeysh Omprakash Mehra's Delhi-6 opposite Abhishek Bachchan. The film received mixed reviews by the critics, but her performance was highly praised. Critic Rajeev Masand commented, "Sonam Kapoor is the revelation in Delhi 6. She's a firecracker performer, instinctive and uninhibited in what isn't even a conventional female lead". Kapoor had signed David Dhawan's comedy film Come On Pappu, in which she is paired with Akshay Kumar. However, the movie has been shelved. Currently, she is shooting for Aisha and will soon start to shoot for Karan Johar's I Hate Luv Storys with co-star Imran Khan