Nayanthara was born into a Orthodox Syrian Christian family, in Tiruvalla, Pathanamthitta District, Kerala. She did her schooling at various parts of India (Kerala and Tamil Nadu), as her father was an Air Force Official. She joined Balikamadom High School, Thiruvalla for +2, then joined Marthoma college in Thiruvalla for her Bachelor's degree (English Literature).
Nayan Tara who was Diana Mariyam Kurien then was chosen 1st runner up in Best model Kerala 2003 which was conducted by Thrissur Advertising Club. This gave her few opportunities in modelling for adverisements. While at college, she was spotted by director Satyan Anthikkad and cast opposite Jayaram in Mansinakkare. Afterwards, she co-starred alongside Mohanlal in Naatturajaavu and in Fazil's Vismayathumbathu. She was also cast with Mammootty in Thaskaraveeran (Dubbed into Tamil as Yuvaraj) and Raapakal.
She has also starred in several Tamil and Telugu movies. She was cast opposite Sarath Kumar in Ayya and with Rajnikanth in Chandramukhi. Her later films are Vallavan (Tamil), Gajini (Tamil), Yogi (Telugu) etc. flopped except Ghajini. She regained her throne in Kollywood through Billa in 2007. Her next movie Yaaradi Nee Mohini was a stupendous success. Nayanthara is currently a leading star in Southern Cinema, with leading roles in films with Rajnikanth - Kuselan, with Ajith Kumar - Aegan, with Vijay - Villu, with Vishal - Sathyam and an untitled film with Surya. She is currently the highest paid South Indian actress. She was paid Rs. 1 crore for Sathyam and Kuselan .
Nayantara is very generous person, who has contributed to several causes. While working with Rajini, who is known for giving away gifts such as chains to people on the sets to celebrate a movie's success or to reward his coworkers, she became intrigued by his kind gestures. Inspired by this, she also started to reward her co-workers in her other movies by giving away gifts such as bicycles. She is a down to earth and a darling among technicians for the exemplary camaraderie she exhibits with them. During shoots Nayan always stays at the floor, unlike other stars, who shut themselves up in the vanity vans. She contributed INR 5,00,000 (5 lakhs) to TN Chief Minister as relief aid for displaced Sri Lankan Tamils, at a celebrity fast arranged in solidarity with the Tamils of Sri Lanka. Her donation was the heftiest sum given by an actress, this despite the fact that Nayanthara is not a Tamil herself.
Nayantara created headlines when publicity posters of her movie Vallavan sprung up around Chennai showing her Vallavan co-star, Silambarasan and her kissing, who she was rumoured as involved with at the time. However, the pair broke up citing differences soon after the film was released. Further controversy was created when rumours leaked out that the plot of Silambarasan's forthcoming film, Kettavan, was based on the couple's true love story.