Sujatha was the pseudonym of the Tamil author S. Rangarajan, author of over 100 novels, 250 short stories, ten books on science, ten stage plays, and a slim volume of poems. He was one of the most popular authors in Tamil literature, and a regular contributor to topical columns in Tamil periodicals such as Ananda Vikatan, Kumudam and Kalki. He had a wide readership, and served for a brief period as the editor of Kumudam, and has also composed screenplays and dialogues for several Tamil movies.

In addition to the novels, stories, essays he wrote, he helped introduce haiku poetry to Tamil audiences. Brought up in Srirangam, Trichy, and having spent most of the later part of life in Bangalore, he described both places vividly in his various compocings. Among his popular novels are Pirivom Sandhipom (not related to the recent movie of the same name), Rathham Ore Niram, and Kolaiyudhir Kaalam.