Krish was born in the town of Tiruchirappalli, Tamil Nadu but shifted to New York after his father, a banker, had moved abroad on a posting. He thus shifted schools and spent 15 years in the USA. During his time in New York, Krish worked as an assistant on the sets of the The Cosby Show and National Treasure: Book of Secrets (2004), helping the teams conduct pre-production works. He also completed an acting course at the New York Film Academy and performed at the Broadway in a Walt Disney production of Aladdin, before arriving in Chennai, hoping to get a breakthrough in the industry as an actor. During the initial months of his return to Chennai, Krish participated in stage shows and cultural events as a singer and was recruited by composer Ganesh Kumar to sing a western song for an album. Ganesh subsequently passed over Krish's details to music composer Harris Jayaraj. He then made his playback singing debut in Tamil films by rendering the song "Manjal Veiyil" from Vettaiyaadu Vilaiyaadu. He consequently collaborated with the composer on several other critically acclaimed songs including "June Ponal July Kaatru" from Unnale Unnale, "Sakiyae" from Dhaam Dhoom, "Oru Mugamo" from Bheema and "Adiye Kolluthey" from Vaaranam Aayiram. He has also featured as a lyricist, penning two songs for the romantic comedy Kandaen (2011). Producer Ibrahim Rowther spotted Krish in the "Aga Naga" song and offered him the chance of portraying the lead role in his production, Puriyatha Anantham Puthithaga Aarambam. The film had a low key opening, and garnered negative reviews. In June 2015, he also released an independent six-track music album, with compositions by Vijay Ebenezer and videos featuring Nikesha Patel. He had worked alongside Ebenezer for two years for the project, with the song "Maaya" from the album being heavily promoted. Krish married actress Sangeetha at a private ceremony at Annamalaiyar Temple in Tiruvannamalai on 1 February 2009. They have a daughter, Shiviya.