S. Ramesan Nair (3 May 1948 – 18 June 2021) was an Indian lyricist and poet who worked predominantly in the Malayalam film industry. Over his career he wrote songs for over 170 films and over 3,000 devotional songs outside of the films. He debuted with the movie Pathamudhayam in 1985. He was a recipient of the Kerala Sahitya Akademi Award in 2010 and the Kendra Sahitya Akademi Award in 2018 for his collection of poems Gurupournami.

S. Rameshan Nair was born on 3 May 1948 in a village named Kumarapuram in the present-day Kanyakumari district, in Tamil Nadu, as the son of late Shadananan Thampi and late Parvathi Amma.^[1] Being born in an area with high Tamil influence, he was equally fluent in both Malayalam and Tamil. Due to the intense passion towards poetry, he dropped his admission for MBBS and graduated with a bachelor's degree in economics in 1966 and later completed his post graduation in Malayalam Literature in 1972. He worked as a sub editor in Kerala Bhasha Institute and also worked with the All India Radio as a producer.^[1]

Nair was a playwright, lyricist, translator and commentator of classical Indian literature such as the Tamil works Chalappathikaram and Tirukkuṟaḷ. He achieved wide appreciations as a poet through works like Sooryahridayam, before starting his accomplished career as film lyricist in 1985 by penning songs for the movie Pathamudayam. He wrote songs for 170 films and 3,000 devotional tracks.^[2]

Nair was married to his wife P. Rama, a school teacher. The couple had a son, Manu Ramesan, a music composer in the Malayalam movie industry. Nair died at the age of 73 on 18 June 2021, at Lakshmi hospital in Ernakulam, due to COVID-19^{[11][1][12][6]} related complications. He was diagnosed earlier with cancer, and also suffered from many other illnesses.^[3] He was cremated with full state honours on the next day. He is survived by his wife Rema, son Manu and granddaughter Mayika.