Sangeetha was born in Chennai, India, to Arvind and Bhanumathy. Her grandfather, K. R. Balan, is a film producer, who had produced more than 20 Tamil films. Also her father had produced several films. She has two brothers. Sangeetha is a Bharatanatyam dancer as she had learned Bharatanatyam during her school days.^[4]

She started her acting career in the late 1990s, beginning in an unreleased film opposite Venkat Prabhu titled Poonjolai. But eventually her debut release was the big-budget Malayalam political thriller, Gangotri. She subsequently played small roles in successful films like Summer In Bethlehem, Kaadhale Nimmadhi etc. She was cast as a second-heroine in the Mammootty-starrer Ezhupunna Tharakan. She also earned a small role in the Mohanlal-starrer Sradha. Her supporting roles in Khadgam and Pithamagan earned her Filmfare Awards in Telugu and Tamil.

She is a judge on Vijay TV's hit show Jodi No.1. She was one of the three judges along with Silambarasan and Sundaram in Jodi No.1 Season Two and with S.J.Suryaah and Sundaram in Jodi No.1 and with Jeeva and Aishwarya Dhanush in Jodi No.1 Season Three.

She was a guest judge during the finals of Vasantham Central's Indian dance competition "Dhool" held in Singapore in 2008.

She got married to film playback singer Krish on 1 February 2009 at the Arunachaleshwarar Temple in Thiruvannamalai.,^[5] which was attended by several noted film personalities. In 2012, their first daughter was born.^[6]