In 1998, she and her then adviser Jonathan Keating conjectured a value for the leading coefficient of the asymptotics of the moments of the Riemann zeta function. Keating and Snaith's guessed value for the constant was based on random-matrix theory, following a trend that started with Montgomery's pair correlation conjecture. Keating's and Snaith's work extended works by Conrey, Ghosh and Gonek, also conjectural, based on number theoretic heuristics; Conrey, Farmer, Keating, Rubinstein, and Snaith later conjectured the lower terms in the asymptotics of the moments. Snaith's work appeared in her doctoral thesis Random Matrix Theory and zeta functions.
Nina Snaith is the sister of mathematician and musician Dan Snaith.
In 2014 Snaith Delivered the 2014 Hanna Neuman Lecture  to honour the achievements of women in mathematics.