For his roles in the movie Karthi would practice by removing his jeans and wearing Lungi all the time.
Karthi married Ranjani in 2011 at CODISSIA trade fair complex, Coimbatore. She is M.A English Literature major from Stella Maris College, Chennai
When he was in New York, Karthi worked as a part-time graphic designer.
Karthiwanted to become a director, after his education he became an assistant to direcor Maniratnam
Mani Ratnam offered Karthi a significant role in Aayutha Ezhuthu, but he declined it as he wanted to become a director.
Karthi inaugurated "Makkal Nala Mandram", a social welfare club of like minded
Karthi worked as an Engineering consultant after his graduation and was thinking of higher studies before becoming an assistant director.
Karthik & Charity: Karthi donates blood regularly, through his charity organizatino he helps poor kids with books, bags and bicycles, he donates money to help AIDS affected children. He has been ambassdor of many awareness campaigns.
He promotes awareness about lysosomal storage disease
Karthi & Rajani were engaged on 29 April 2011 at Goundampalayam, Erode, native place of Rajani
Paruthiveeran, a 2007 movie became the turning point, it got him acclaim as an actor.
Karthi is the younger brother of actor Tamil actor Suriya
In 2015, he worked as the treasurer of the Nadigar Sangam.
Karthi is the stage name of actor Karthik Shivakaumar
Karthi adopted a white tiger cub at Vandalur Zoo and donated towards preserving it.
Karthi attended two separate courses in film making at New York State University
Karthi became brand ambassador of Bharti Airtel in South India
Karthi visits orphanages and donates funds to them On his birthdays.
His appearance for the Bru Coffee Ad along with Kajal Aggarwal is televised throughout India
Karthi won Filmfare Award for Best Actor and a Tamil Nadu State Film Award for his first movie as an actor- Paruthiveeran(2007)
On his journey to film industry "I was earning about INR 5000, per month and found the work monotonous. That was when I thought, I should do something more"
When asked about his wife's reactions to his romantic movies "None of the wives like love stories. They don't like to see their husband romancing other ladies"