Karthika Nair (born 27 June 1992) is an Indian film actress in the South Indian film industry. She made her debut in the 2009 Telugu film Josh, opposite Naga Chaitanya. She rose to fame starring in her second and her first successful Tamil film Ko, opposite Jiiva and Piaa Bajpai with ko. She found further success in the Malayalam film Kammath & Kammath, opposite Dileep. She is well known for her action roles in the comedy Brother of Bommali, the social drama Purampokku Engira Podhuvudamai and the epic TV series Aarambh.
Karthika was born to former Indian actress Radha, and is the niece of actress Ambika. She has two siblings, a brother and a sister, Thulasi Nair, who is also a South Indian actress. She did her schooling in Podar International School in Mumbai and studied for an international degree in Business from college affiliated to London School of Economics.
She made her acting debut at the age of 17 in the 2009 Telugu film Josh, opposite Naga Chaitanya. Though the film received mixed reviews, her performance as Vidya, an elementary school teacher desperate to attend college was received well. She received the Santosham Film Award for Best Debut Actress. Her second movie was in Tamil, called Ko, directed by famous film director K. V. Anand, with Jiiva and Piaa Bajpai in lead roles, which did very well at the box office. The film received cult status in the genre of political thrillers. Her performance as Renuka Narayanan, an investigative journalist, who exposes the blunders of politicians was hugely applauded. She received nomination for SIIMA for Best supporting Actress – Tamil at 1st South Indian International Movie Awards. She then appeared in the Malayalam film Makaramanju, directed by Lenin Rajeendran, starring alongside ace cinematographer and director Santosh Sivan. She donned a dual role, one of a painting model, Sugandha Bai and Urvashi, the Celestial beauty. Her first ever dual role was well received and critics raved about her performance. British director Danny Boyle was highly impressed with her work in the film. She received SIIMA for Best Debut Actress – Malayalam at 1st SIIMA Awards and Kerala Film Critics Association Award for best debut actress.