Siddharth is born in Chennai in 1979. He completed his schooling in Chennai and Delhi and was graduated with Commerce (Honors) degree from Kirori Mal College, New Delhi. He later pursued his MBA degree from S. P. Jain Institute of Management and Research, Mumbai. With his bright managerial skills, he went on to win CNBC Manager of the year award in 1999.

Siddharth is linked up with Shruti Hassan, Soha Ali Khan in his career but later parted ways with them. Currently he is seen moving closely with Samantha. Both of them with their families attended a puja ritual in Srikalahasthi. But the couple remained tightlipped about their relationship.

Siddharth was always a part of theater groups during his college days. His oratory skills were too good that he even represented his college at international debate competitions.  He joined as assistant director to Mani Ratnam Tamil film, Kannathil Muthamittal (later dubbed in to Telugu as Amrutha). During the movie shoot, the script writer of that film, Sujatha urged him to attend the audition of Shankar's Boys. He was selected and made his filmy debut with that movie. The movie was an average grosser but brought him good name in audience. In the next year, he appeared in Mani Ratnam’s Aaytha Ezhuthu (dubbed in to Telugu as Yuva).

The major break to him came in the form of Nuvvosthanante Nenodhantana, the debut movie of Choreographer Prabhudeva. Siddharth became dearer to Telugu audience with his boy next door looks and from then there is no looking back. Even though his next movie, Chukkalo Chandrudu failed at the box office, His maiden Bollywood film, Rang De Basanti and Telugu film, Bommarillu which released in the same year went to become blockbusters.

The result of Bommarillu had adverse effect on Siddharth’s career. Due to the high expectations set by the movie led Siddhu to flop track. In the later years, Siddharth had 11 releases (Aata, Konchem Ishtam Konchem Kashtam, Oye, Bava, Anaganaga O dheerudu, 180, Oh My Friend, Love Failure, Jabardasth, NH4 and Something Something) in Telugu all failed at the box office. On the other side, he maintained decent success rate in Tamil.  Something Something even though failed in Telugu went to become good hit in Tamil. However things became even difficult for Siddharth in Telugu after Something Something. There were no takers even for the dubbing rights of his films and even the taken ones do not release. However he continue to go films in Tamil. His recent film in Tamil, Kaaviya Thalaivan has got good report but yet the film did not get dubbed in to Telugu.

Siddharth turned writer with Chukkallo Chandrudu movie and producer with his bilingual movie, Love Failure under his production house, Etaki Entertainment.

Siddharth is always known for his controversial side.  Here are some of the controversies involving him:

• During the release of his 180 movie, he reacted heavily on a News channel’s program. He tweeted, 3rd grade 'N'ews channels will sell their families to make up an hour of TV. Clarifying their garbage & lies is not worth our time. Ignore!" At a press conference held the next day to talk about 180 in Hyderabad, when Siddharth took to the stage, all the cameramen switched off their cameras and pulled their mics back, as per their plan.
• Siddharth's war on media did not end there. He launched a scathing attack on media once again in an interview to a National Newspaper (on Samantha issue), "I have been written about with a lot of women. I have chosen not to respond. My family does not read gossip rags and what is in the paper today is the packing for a pakoda tomorrow. You can attribute a quote to a person without meeting him. The inverted comma is being molested beyond identity."

• During a press meet of his Kadhalil Sodhapuvadhu Eppadi in Chennai, Siddharth came in to bad lights with his indirect comments on the taste of Telugu audience. He attributed the failure of the Telugu version of Kadhalil Sodhapuvadhu Eppadi (Something Something) due to the bad taste of Telugu audience.