Avadhesh Narayan Singh (Benares, 1901 – July 10, 1954) was an Indian mathematician and historian of mathematics.
Singh received a master's degree from Banaras Hindu University in his hometown (Varanasi was then called Banaras or Benares) in 1924, where he was a student of Ganesh Prasad. He received his DSc in mathematics from the University of Calcutta in 1929 for his dissertation titled "Derivation and Non-Differentiable functions". After securing a DSc, Singh went to Lucknow University, where he became a Reader in 1940 and a professor in 1943. There he opened a Hindu Mathematics section and revived the nearly defunct Banaras Mathematical Society under the name of Bharata Ganita Parisad. In the 1930s he wrote a history of Indian mathematics with Bibhutibhushan Datta, which became a standard work. As a mathematician, he dealt with non-differentiable functions (an example of an everywhere non-differentiable function is the Weierstrass function).[1][2]