Dhanush's first film was Thulluvadho Ilamai, a 2002 coming-of-age film directed by his father, Kasthuri Raja. Over the next ten years, Dhanush has starred in over 25 films. Dhanush won the Best Actor award at the 58th National Film Awards for his performance in Aadukalam (2010). In 2011, Dhanush received international attention with his popular song "Why this Kolaveri Di", which became the first Indian video song to cross 100 million views on YouTube. Dhanush produces films under his production company, Wunderbar Films. He has won 3 National Film Awards and 7 Filmfare Awards.
Born to Tamil film director and producer Kasthuri Raja, Dhanush entered acting after being pressured by his brother, director Selvaraghavan. Dhanush married Aishwarya, Rajinikanth's daughter, on 18 November 2004. They have two sons named Yatra and Linga who were born in 2006 and 2010. He studied at the Thai Sathiya Matriculation High School.
Dhanushan debuted in the film Thulluvadho Ilamai, directed by Kasthuri Raja, which received mostly positive reviews from critics and the public. He then appeared in his brother Selvaraghavan's first directorial venture, Kadhal Kondein. The film portrayed Dhanush as a mentally-disturbed youth, Vinodh, who yearned for the love of his friend, eventually turning possessive over her. Upon release, the film won critical acclaim and additionally became a major commercial success. His next film, released later in 2003, was Thiruda Thirudi.
Dhanush appeared in Pudhukottaiyilirundhu Saravanan and Ramana's Sullan. Later, he additionally appeared in Dreams, another film panned by critics. The film was directed by his father, like their previous ventures. In 2005, Dhanush appeared in Devathaiyai Kanden. Later it was dubbed into Telugurert, and in quite same year he additionally worked on Balu Mahendra's Adhu Oru Kana Kaalam.
Pudhupettai re-united Dhanush with his brother. Dhanush's portrayal was praised by critics. The Telugu dubbed version was titled Dhoolpet. Dhanush went on to star in the commercial entertainer Thiruvilayadal Arambam romancing Shriya Saran.
Dhanush's first release of 2007, Parattai Engira Azhagu Sundaram didn't go well. The film, which was a remake of the successful Kannada language film, Jogi'. Notwithstanding his second film Polladhavan was released throughout Diwali 2007. Polladhavan was based on 1948–Italian neorealist film The Bicycle Thieves and Dhanush's performance was appreciated.
The remake of a Telugu film directed by his brother formed the plot line for Dhanush's next movie directed by debutant Mithran Jawahar. The movie titled Yaaradi Nee Mohini. He later appeared in a cameo appearance, for his father-in-law Rajinikanth's venture, Kuselan. His subsequent venture was Suraj's Padikathavan which was released in January 2009. His performance was praised and well received. His next two films Kutty and Uthama Puthiran, were both collaborations with director Mithran Jawahar.
Dhanush's first release in 2011, which he had shot for over three years, was Aadukalam, marking his second collaboration with Vetrimaran. Dhanush played the role of a local cockfighter and described the venture as his "Dream Project" throughout production. The film gained highly positive reviews and won six awards at the 58th National Film Awards, with Dhanush receiving the National Film Award for Best Actor, fitting the youngest actor to win the award. Dhanush appeared in an extended guest appearance in Subramania Siva's Seedan. His next two ventures were action-masala films: Mappillai, a remake of his father-in-law's same-titled 1989 film and Venghai, by Hari, which received mixed reviews but was a commercial success.
Dhanush's next film, Mayakkam Enna, in which he again collaborated with his brother, casting him with Richa Gangopadhyay, received largely positive reviews. His only 2012 release was 3 directed by his wife, Aishwarya Rajinikanth with Shruti Haasan. The movie was a moderate success, owing to the popularity of the song Why this Kolaveri Di. In 2013 he appeared in Maryan opposite Parvathi Menon, which was applauded by critics but became an above-average grosser at the box office. His next release was Naiyaandi, directed by A. Sarkunam, which didn't make any notable impact in the box office.
Dhanush's first film of 2014 was Velaiyilla Pattathari, which was additionally his 25 film and was directed by Velraj. It received mostly positive reviews and was a success. His next release was Shamitabh, released in year 2015 which was additionally his second Hindi film directed by R. Balki opened to quite high positive reviews and was praised for the concept but failed at box-office. His next film Anegan was a psychological thriller directed by KV Anand which generated positive reviews and became a box office success.
Dhanush's next release in 2015 was the action comedy Maari, featuring Kajal Aggarwal, Robo Shankar, and Vijay Yesudas. Directed by Balaji Mohan and composed by Anirudh, it was released worldwide on 17 July 2015. He additionally appeared in Thanga Magan directed by Velraj with Samantha, Amy Jackson, KS Ravikumar, and Raadhika Sarathkumar. Dhanush has additionally signed on to seem in his first international film, titled The Extraordinary Journey Of The Fakir Who Got Trapped In An Ikea Cupboard, to be directed by Marjane Satrapi.
Dhanush occasionally records music, generally for his own films. He was introduced as a playback singer in Pudhukottaiyilirundhu Saravanan by its composer Yuvan Shankar Raja and collaborated again with him in his brother Selvaraghavan's directorial, Pudhupettai. He sang further numbers in Selvaraghavan's films Aayirathil Oruvan and Mayakkam Enna; the former featured him alongside his wife Aishwarya Rajinikanth.
"Why this Kolaveri Di" was released on YouTube in 2011 as part of the soundtrack to the film 3, the directorial debut of Aishwarya Dhanush. The song became the most searched video in India and an internet phenomenon across Asia. Anirudh Ravichander was the soundtrack composer for the film and Dhanush wrote much of the lyrics.
Dhanush was a brand ambassador of PETA and named India's hottest vegetarian celebrity of 2011. He worked with WWF India to support Earth Hour 2012. In August 2013, Dhanush was signed by Perfetti India Ltd. as their brand ambassador for Center Fresh chewing gum.