Harald Andrés Helfgott (born 25 November 1977) is a Peruvian mathematician working in number theory.

[1] He received his Ph.D. from Princeton University in 2003 under the direction of Henryk Iwaniec and Peter Sarnak,[1][2] with the thesis Root numbers and the parity problem.

[4] In 2017 Helfgott spotted a subtle error in the proof of the quasipolynomial time algorithm for the graph isomorphism problem that was announced by László Babai in 2015.

[9][10] In June 2010, Helfgott received the Whitehead Prize by the London Mathematical Society for his contributions to number theory, including work on Möbius sums in two variables, integral points on elliptic curves, and for his work on growth and expansion of multiplication of sets in SL2(Fp).

[12] In August 2013, Helfgott received an Honorary Professorship from National University of San Marcos in Lima, Peru.