Arulnithi Tamilarasu is an Indian Tamil actor, Arulnithi was offered the lead role in Pandiraj's Vamsam after his cousin, Udhayanidhi Stalin, had opted out. The film featured him as a young man shying away from the politics of his village, despite claims for him to avenge his father's death.
The film, which featured him alongside Sunaina, was heavily promoted in Tamil Nadu as a result of the influence of his family, and became a profitable venture at the box-office, garnering positive reviews.
His second film was Udhayan in which he essayed a dual role for the first time. His third film Mouna Guru directed by debutant Santhakumar was a critically acclaimed sleeper hit which was also screened at the Hong Kong International Film Festival 2013.
Arulnithi's grandfather is M. Karunanidhi, former Chief Minister of Tamil Nadu. His father is M. K. Tamilarasu, brother of M. K. Stalin, former deputy Chief Minister and Home Minister of Tamil Nadu. He has also produced three of Arulnithi's films. His cousins include noted producers, Udhayanidhi Stalin and Dhayanidhi Alagiri.
Arulnithi was educated at St. Michael's Academy in Chennai, before pursuing a degree at Loyola College. He then went on to Pondicherry University to undertake more qualifications.