Silambarasan Thesingu Rajendran (born 3 February 1983), also known as Simbu or S. T. R., is an Indian film actor, director, writer, music composer, dancer, lyricist and playback singer in the Tamil film industry. He began his career by playing roles as a child artist in films directed by his father T. Rajendar, before his first lead role in Kadhal Azhivathillai (2002), under his father's direction and produced by his mother Usha.
Silambarasan was born on 3 February 1983 in Chennai, Tamil Nadu, as the eldest child of T. Rajendar and Usha Rajendar. He has a younger brother Kuralarasan, and sister Ilakiya. He studied at the Don Bosco Matriculation Higher Secondary School and St. John's Indian Residential School. Simbu entered the film industry from a young age and acted in many of his father's films until 2002, when he acted in Kadhal Azhivathillai, his first main role as a hero.