Rajesh Ramayan "Raj" Koothrappali, Ph.D. (born October 6, 1981) is a fictional character on the CBS television series The Big Bang Theory, portrayed by British Indian actor Kunal Nayyar.
Rajesh is Howard Wolowitz's (Simon Helberg) best friend, with whom Raj shares what Nayyar calls a "bromance", although the relationship is frequently made awkward by Raj's metrosexuality. Raj works as an astrophysicist in the Physics Department at Caltech. His principal characteristic was selective mutism (social anxiety disorder), which did not allow him to talk to women unless he was under the influence of alcohol. He was cured of this disability in the season 6 finale.