Karattuparambil Achuthan Jayaseelan (born 27 July 1940) is an Indian linguist, essayist and a poet of Malayalam literature.

He is known for his poems characterized by philosophical thoughts and his contributions to the linguistics of South Indian languages.

Jayaseelan was born on 27 July 1940 to K. R. Achuthan, a lawyer and Umbooli, a school teacher and the eldest daughter of Mithavaadi Krishnan.

[1] Jayaseelan is married to Amritavalli, an academic, co-author of one of his books and his colleague and the couple have two children, Annapoorna and Maitreyi.

Jayaseelan's poetry is noted for its intense philosophical overtone, often presented in a witty manner.