Sanon was born on 27 July 1990 to Rahul Sanon, a chartered accountant and Geeta Sanon, Professor at the University of Delhi. She has one younger sister, Nupur Sanon. She attended Delhi Public School, RK Puram and completed a BTech degree in Electronics and Communication Engineering, from Jaypee Institute of Information Technology, Noida, Uttar Pradesh. She has appeared in various television commercials, endorsing brands such as: Close Up, Vivel, Amul, Samsung and Himalaya. She modeled for Wills Lifestyle India Fashion Week 2010, held in Mumbai. In 2012, she appeared in Chennai International Fashion week and India International Jewelry week. Kriti has been a favorite of several well-known Indian designers for whom she frequently modeled, like Ritu Beri, Suneet Varma and Niki Mahajan.
Sanon made her acting debut in 2014, with Sukumar's Telugu film 1: Nenokkadine, a psychological thriller, in which she played the role of Sameera. The film generated mixed reviews from critics. The Times of India critics stated Sanon "looks pretty" and "acts well". while the reviewer at Sify.com stated that Sanon "looks gorgeous", though her performance is "okay".
Later that year, Sanon made her Hindi cinema debut with Sabbir Khan's action-romance film Heropanti. Despite the fact that the film received mixed reviews from most critics, Box Office India called it a commercial success at the Indian box office. Taran Adarsh of Bollywood Hungama said she "looks gorgeous and handles her part with certainty and confidence" and that she "has the trappings of a star", whereas Rajeev Masand said she "looks lovely and makes an impression despite her harebrained role". Srijana Das of The Times of India, criticised her emoting, calling it "more cheesy than sharp." For her performance, Sanon won the Filmfare Award for Best Female Debut.
Sanon had her second Telugu release entitled Dohchay directed by Sudheer Varma in 2015. Sanon subsequently appeared in Rohit Shetty's Dilwale in which she starred alongside Varun Dhawan, Shahrukh Khan and Kajol. The film received mixed reviews from critics, though emerged a major commercial success at the box office, grossing more than ₹394 crore (US$61 million) worldwide. While Taran Adarsh of Bollywood Hungama praised Sanon's work and said she "is camera-friendly and confident to the T", Anupama Chopra noted that Sanon, along with Dhawan, "work as bait, meant to bring in the critical youth segment".
In April 2017, she performed in the opening ceremony of 2017 Indian Premier League.
Sanon starred in two films in 2017; in Dinesh Vijan's directorial debut Raabta opposite Sushant Singh Rajput; and in Ashwiny Iyer Tiwari's Bareilly Ki Barfi alongside Aayushmann Khurrana and Rajkumar Rao.
In addition to acting, Sanon is an endorser for several brands and products, including Trident Group's – Bath & Home Linen, Titan Watches-Raga Collection, the hair product Parachute, apparel brand American Swan and a cola brand, among others. In July 2014, Sanon launched Tissot's Quickster Football watch in multiple cities in India.