Doctor Sivasubramanian Chandrasegarampillai (often abbreviated to Dr. Chandra) is a fictional character from Arthur C. Clarke's Space Odyssey series.
He is mentioned in the novelization of 2001: A Space Odyssey as a scientist who instructed the computer HAL 9000 in its basic functions (in the movie, it was a "Mr. Langley"). He is a main character in 2010: Odyssey Two as a member of the joint Russian-American expedition to Jupiter on board the Soviet spacecraft Alexei Leonov. He is also briefly mentioned by an elderly Heywood Floyd in the novel 2061: Odyssey Three.
In the movie version of 2010, Dr. Chandra was played by Bob Balaban and is referred to as Dr. R. Chandra.