Sai Deena is an Indian actor and stuntman who has appeared in more than 60 Tamil-language films since 2004. He often plays the antagonist in his films, including Attu, Thimiru Pudichavan, and Vaandu. He has also worked with Atlee on many projects.

Deena is also a social worker who helped many people who lost their livelihoods during the coronavirus pandemic. In November 2022, Deena and his family converted to Buddhism, taking 22 vows in the presence of a Buddhist monk. A photo of Deena, his wife, and their three children with the monk went viral on social media.
 
Deena comes from a humble background and started his career as a billboard painter. He later took on small roles as henchmen to larger-than-life Tamil heroes before moving on to supporting roles.