Karthik Sivakumar (born 25 May 1977), known professionally as Karthi, is an Indian actor who is known for his works in Tamil Cinema.

After a three-year hiatus from acting, he then return to star in films such as Aayirathil Orvuan, Paiyaa and Naan Mahaan Alla, all three of which were released in 2010.

Karthi has starred in several well-known Indian films, portraying an impulsive and short-tempered working-class man in Madras (2014), a paroled convict-turned-caretaker in Tamil-Telugu bilingual comedy-drama film Oopiri / Thozha, and in dual roles as the titular protagonist and the antagonist Raj Nayak in Kaashmora (both in 2016).

[7] In October 2006, Karthi signed his second project under Selvaraghavan's direction,[8] Idhu Maalai Nerathu Mayakkam, which was supposed to be a romance film,[9] featuring Sandhya as the female lead.

[11] Selvaraghavan abandoned that project and in July 2007, he announced the production of an action-adventure film titled Aayirathil Oruvan, with Karthi in the lead role.

[16] During the filming of Aayirathil Oruvan, producer R.Ravindran complained that Karthi was trying to change his look and move on to Paiyaa before finishing his commitments.

[23] Karthi's performances in Aayirathil Oruvan and Paiyaa earned him further nominations at the 58th Filmfare Awards South in the Best Actor category.

[citation needed] Karthi's third film in 2010 was Suseenthiran's action thriller Naan Mahaan Alla, in which he played a middle class youth from Chennai whose life is disrupted when his father is targeted by a gang of killers.

"[25] Bhama Devi Ravi of Times of India wrote: "  ...  what a pleasure to see Karthi deliver his best performance to date  ...

[26] Rediff wrote that "Karthi has simply had a ball ... " and "It's been a long time since you saw an actor who can be as convincing in sadness and rage, as in happiness.

[30] Pavithra Srinivasan of Rediff wrote: "But the film belongs to Rocket Raja (Karthi), the sort of adorable ruffian Tamil cinema has been missing for a while.

[33] He made a special appearance in a song in K. V. Anand's Ko (2011), alongside other prominent actors from Tamil cinema (Incl.

[34] In May 2011, Karthi began working in the political comedy film Saguni, directed by Shankar Dayal and featuring him amongst an ensemble cast of supporting actors.

[35] He played Kamalakannan in the film, a villager who comes to the city to save his palatial house in Karaikudi from being destroyed for a politician's personal gain and unknowingly transforms to become a kingmaker in Tamil Nadu politics.

[citation needed] Karthi's performance was praised, with Baradwaj Rangan of The Hindu stating (in his review of the Tamil version Thozha), "At a time every leading man (including Karthi) seems to be participating in a game-show titled Who Wants To Be The Next Rajinikanth?, here's a simple 'buddy movie' (in the Hollywoodian sense), with no punch dialogues, no action sequences, with just one duet (with Tamannaah, who plays Vikram's secretary; her romance with Seenu is strangely unresolved).

[47] Right after Theeran Karthi acted in Kadaikutty Singam portrayed the role of a farmer directed by Pandiraj which has been produced by this brother Suriya which has gained the highest footfalls in the year 2018 in Tamil Nadu.

[48] His next film was Dev, produced by Lakshman Kumar, under Prince Pictures, directed by debutante director, Rajath Ravishankar, music composed by Harris Jayaraj, and cinematography by R. Velraj.

He has two siblings; an elder brother, Suriya, who was already an established actor at the time of Karthi's film debut, and a younger sister, Brindha, who is a singer in Tamil cinema.

[53] Karthi got a scholarship for his higher studies in the United States,[55] and enrolled at Binghamton University, New York, where he earned his Master of Science in industrial engineering.

[55] On 3 July 2011, Karthi married Ranjani Chinnasamy,[57][a] who graduated with a master's degree in English literature from Stella Maris College, Chennai.

[59] They were engaged on 29 April 2011 at Ranjani's native village, Goundampalayam in Erode district,[57] and the wedding was held in a traditional Kongu culture at the CODISSIA Trade Fair Complex in Coimbatore.

On his 31st birthday, he inaugurated the Makkal Nala Mandram,[63] in order to encourage his fans to become involved in welfare activities.

[citation needed] He had also adopted a white tiger cub at Vandalur Zoo and contributed ₹ 72,000 to protect and preserve the animal.

[65] In September 2010, Karthi signed a contract with Bharti Airtel to become its brand ambassador in South India and appear in its "Indraikku enna plan" advertising campaign.

[66] He has also appeared in advertisements for Bru Instant Coffee along with Kajal Aggarwal, who had earlier acted opposite him in Naan Mahaan Alla and All in All Azhagu Raja.

[citation needed] In 2015, Karthi joined fellow actors Vishal, Nassar, Karunas and Ponvannan to campaign against the concurrent office bearers of the Nadigar Sangam, led by R. Sarathkumar and Radha Ravi.