S. Janaki (born April 23, 1938) is an Indian playback singer. She has sung in many Indian languages including Telugu, Tamil, Malayalam and Kannada. Janaki is also a lyricist and a music composer. A devotee of Lord Krishna and Shirdi Sai Baba, she spends a lot of time praying and has also released devotional music cassettes on Meera.

S. Janaki was born in Pallapatla, Repalle village, Guntur District of Andhra Pradesh

Janaki showed interest in music at a tender age and started singing at the age of three. She started learning music from a nadaswaram vidwan, Sree Paidiswamy. She moved to Chennai on the advice of her uncle Dr. Chandrashekar and joined as a singer in AVM Studio and started her career with Tamil films in 1957 in the film 'Vidhiyin Vilayattu' under the music director T. Chalapati Rao. Later, she got a chance in a Telugu film MLA.

She wrote many songs for Tamil and Telugu films. She has sung many songs, in almost all languages in South India as well as in Hindi, Sinhalese, Bengali, Oriya, English, Sanskrit, Konkani, Tulu, Saurashtra, Baduga, Japanese and German. Major singers along with her are P. Susheela, Vani Jayaram, K J Yesudas, P. Jayachandran, K. S. Chithra and S P Balasubramanyam.

Her husband is late Sri.V.Rama. She lives with her son Murali Krishna, who acted in few films and has an audio business of his own; and his wife Uma Murali Krishna, a classical dancer (Bharatnatyam and Kuchipudi); they have two daughters Amruthavarshini and Apsara.