Prapanchan (Tamil: பிரபஞ்சன்), is the pseudonym of S. Vaidyalingam (Tamil: சாரங்கபாணி வைத்தியலிங்கம்) a Tamil, writer and critic from Puducherry, India.

He started his career as a Tamil teacher in Thanjavur. He also worked as a journalist in Kumudam, Ananda Vikatan and Kungumam. In 1961, he published his first short story Enna ulagamada in the magazine Bharani. He was influenced by the Self-Respect Movement. He had published 46 books. In 1995, he was awarded the Sahitya Akademi Award for Tamil for his historical novel Vaanam Vasappadum (lit. The Sky will be ours) set in the times of Ananda Ranga Pillai. His works have been translated into Hindi, Telugu, Kannada, German, French, English and Swedish. His play Muttai is part of the curriculum in Delhi University and his short story collection Netrru Manidhargal is a textbook in many colleges.