Princeton University math professor Manjul Bhargava, who was born in Hamilton, received the Fields Medal on Wednesday in Seoul.
The medal, which is math's highest honour, was first awarded in 1936 and was named after another Canadian mathematician — John Charles Fields, who also born in Hamilton.
It is managed by the International Mathematical Union, who say Bhargava is being recognized "for developing powerful new methods in the geometry of numbers."
The Fields Medal and a cash prize of US$13,700 are awarded every four years to mathematicians 40 years old or younger.
Four people received the prize this year, including Maryam Mirzakhani of Iran — the first female recipient — Artur Avila, a Brazilian-born professor at the Institute of Mathematics of Jussieu in Paris and Martin Hairer of the University of Warwick in England.