Rajesh "Raj" Ramayan Koothrappali, Ph.D. is a fictional character on the CBS television series The Big Bang Theory, portrayed by British actor Kunal Nayyar. He is one of the four characters, along with Howard Wolowitz, Sheldon Cooper, and Leonard Hofstadter, to appear in every episode of The Big Bang Theory. Raj is based on a computer programmer that the show's co-creator, Bill Prady, knew back when he himself was a programmer.
