Nayanthara was born as Diana Mariam Kurien in Bengaluru, Karnataka, into a Malayali Syrian Christian family. Her father, Kurien Kodiyattu, served in the Indian Army, so she studied in different cities such as Chennai, Jamnagar, Delhi, and Gujarat. After her father retired, the family settled in Kerala, where she completed her college education.

In 2003, while she was still in college, director Sathyan Anthikad noticed her and gave her a role in a Malayalam film. She later acted in Tamil, Telugu, and Kannada movies. She gained fame for starring opposite leading actors like Rajinikanth and Mohanlal.

In 2011, she converted to Hinduism at an Arya Samaj temple in Chennai and officially adopted the name Nayanthara. With her beauty, confidence, and strong performances, she has become one of the most popular actresses in South Indian cinema..