Sithara was born in Kozhikode, Kerala to Dr. K. M. Krishnakumar, noted academician and his wife Saly Krishnakumar. Born into a family inclined to classical arts, Sithara was introduced to the world of music as a child and started singing at an early age of four. She attended St.Paul's Higher secondary School, Thenhipalam and Calicut University Campus School. She did her graduation in English Literature from Farook College, Feroke and went on to pursue her Master's degree in the subject from Calicut University, Kerala. She is married to Dr. M. Sajish (Clinical Cardiologist) on 31 August 2009 and is currently residing at Aluva, Kerala. The couple had a baby girl born on 9 June 2013. She started off her art life as a dancer and eventually became a playback singer.She was trained in Carnatic Music by Sri Ramanattukara Sathish and Palai CK Ramachandran. Sithara also received extensive education in Hindustani Classical music from Ustad Fiyaz Khan and Sri Vijayasenan. She is also a classical dancer trained by Kalamandalam Vinodini. For her multifaceted talents, she was accoladed with the Kalathilakam title in Calicut University Arts Festival for two consecutive years(2005 and 2006). She holds Masters' degrees in Hindustani Khyal Music and Vocal Music from Rabindra Bharati University, Kolkata.
Sithara Krishnakumar is the latest singing sensation of Malayalam cinema. Enundodee song of Celluloid (2013) helped her to win the recently announced Kerala state awards in Best Female playback category. Though she has become a part of Malayalam film industry in 2007, this single award winning song made her a popular singer. The movie contained only two songs and both were composed using instruments of early 1900’s in that style and both the songs gave a new warm nostalgic feeling to its listeners. Celluloid along with its songs – Kaatte kaatte and Enundodee remain at top position till now. Apart from Malayalam, Sithara Krishnakumar has done playback singing in all the rest south Indian languages. She has won Kalathilakam title in Calicut University Arts Festival for two consecutive years(2005 and 2006).