A. Santhosh Kumar (born 5 July 1986), known professionally as Sandy, is an Indian actor and choreographer who works in Tamil and Malayalam films and television. He starred in films such as Leo (2023), Niram Marum Ulagil (2025) and ' (2025).
Sandy gained popularity in Tamil films for his dance choreography in "Pathala Pathala" and "Monica", and special appearance songs in films like Love Today. In 2019, Sandy participated as a contestant on the reality television show Bigg Boss 3 and emerged as the runner-up.
He choreographed for actor Sathish Krishnan and Jayashree throughout the season. He is one of the judges in Kings of Dance season 2. He worked as a choreographer for the Telugu and Kannada language shows Challenge Show and Kuniyona Bara.
He started his choreography career in Tamil film industry through the film Aaaah in 2014. Later he choreographed Viraivil Isai, Ivanuku Thannila Gandam and Vaalu in 2015. He also choreographed for the movies Saagasam, Jithan 2 and Gethu. He further went on to choreograph songs for Rajinikanth in the 2018 film Kaala. As an actor, Sandy made his debut in the movie Ivanuku Thannila Gandam, a comedy film featuring Deepak Dinkar.
In 2019, Sandy appeared in the reality television show Bigg Boss 3 on Star Vijay as a contestant, finishing as the runner up.
In 2021, he appeared in the horror film ' as the lead. A reviewer of The Times of India stated, "The film then throws stuff like semi-evil numbers, mediums who communicate with ghosts and more scenes with Kathir [Sandy] that may or may not be bad dreams, but by then, the film stops being truly scary and turns exhausting". In 2023, he appeared in the film Leo alongside actor Vijay where Sandy portrays the character of a robber.
In 2022, Sandy was the initial cast for the role Samson in the Kannada film Head Bush which starred Dhananjaya. However he opted out of the role and was replaced by Balu Nagendra.
In 2025, Sandy choreographed the song "Monica" for the Tamil film Coolie. Then he made his Malayalam debut in the superheroine film as the antagonist, Inspector Nachiyappa Gowda. It emerged as the highest grossing Malayalam film of all time. He is also playing a role in the ' alongside Jayasurya and Anushka Shetty. He also made his Telugu debut in the horror film Kishkindapuri as the antagonist Vishrawaputra.
Sandy also signed a role with Malayalam director Dhananjay Shankar in the action thriller film Bha. Bha. Ba.. In 2026, he announced his lead role in a Tamil alongside Kavin and Priyanka Mohan which is currently undergoing filming and production and is titled #Kavin09.
Sandy married actress Kaajal Pasupathi in 2008, however the couple later decided to divorce in 2012. He later married social media influencer Dorathy Sylvia in 2017 and have 2 children.