Prof. Nishtala Appala Narasimham, shortly N. A. Narasimham M.Sc., Ph.D. (15 August 1922 – 8 April 2002) was an Indian physicist and eminent Spectroscopist. He was born at Parlakimidi on 15 August 1922. He was graduated in Physics (B.Sc.) from Andhra University in 1942 and M.Sc. in Physics from Banaras Hindu University (BHU) in 1945. He passed both the examinations with first-class. He has worked as lecturer in Physics in Mrs. A.V.N. College, Visakhapatnam and at Bijapur between 1945 and 1949. He has joined with R. K. Asundi at BHU in 1949 and obtained his Ph.D. in 1952.