Sankaramanchi Janaki (born 12 December 1931), popularly known as Sowcar Janaki, is a south-Indian actress who has acted in over 387 Telugu, Tamil, Kannada, Hindi and Malayalam films. She also performed on stage in over 300 shows and was a radio artist during her earlier years. Her career as film actress began only after her marriage. She became a popular actress with hits in various languages between 1949 and 1975 as the lead heroine such as Sowcar (Telugu), Valayapathy, Rojulu Marayi (Telugu), then in Tamil, such as Naan Kanda Sorgam, Kaviya Thalavi, Bhagya Lakshmi, Pallum Pazhamum, Paar Magale Paar, Thayikku Thalaimagan, Kumudham, Panam Paadithavan, Puthiya Paravai, Bama Vijayam, Oli Villaku, Ethir Neechal, Maanavan, Uyardha Manidhan, Nimarundhu Nil, Thunaivan, Needhi and Iru Kodugal (Tamil), with Kannada films such as Devakaanika, Saaku Magalu, Sadarame, Thayige Thakka Maga and then with her Malayalam debut Schoolmaster (1964) and with a film in Hindi - Teen Bahuraniyan. She worked with famous directors such as Dada Mirasee and K. Balachandar. She moved to supporting roles after 1975 and her performances in Cinema Paithiyam, Thee, Thillu Mullu, Vetri Vizha and Kaanche were widely appreciated. She served as jury member for the National Indian Films awards committee and as chair person for state Telugu Films awards committee.

She made her debut at the age of 18, after her marriage, in 1949 with the film Shaukar. After this, she essayed wide variety of roles for next 68 years. The only other actors to have had such long careers in the field of acting in India were Dev Anand, Pran, Ashok Kumar and Kamini Kaushal However, by 2016, her career span has overtaken most of the actors and she remains the actress with the longest career span.

She was the most comfortable on being paired with Gemini Ganeshan and Shivaji Ganeshan repeatedly. She quoted in an interview on her pairing with Sivaji Ganesan, "He would compliment me in public using superlatives. I’d be thrilled! We would always rehearse together. If my character needed a little over-acting, he would tone down his and vice versa. It was a challenge working with the great actor! If they remember Sivaji Ganesan, they remember me". She has done around 387 films in Hindi, Bengali, Malayalam and Telugu.

She actively participated in drama troupes and did live drama shows right from 1960, despite being a busy film star and continued doing so till 1995. In many of the dramas, she worked with co-star Sreekanth