The International Mathematics Union awarded the prize to Maryam Mirzakhani and three others at a meeting in Seoul on Wednesday.
The prize and $13,700 is awarded every four years to mathematicians 40 years old or younger. It was established in 1936.
Mirzakhani, 37, won for complex theoretical math on the symmetry of curved surfaces, including spheres and even doughnuts.
Mathematics has long been dominated by men, with women comprising 28 percent of the doctorates in mathematics and statistics in 2011-2012, only 5 percentage points up from two decades earlier, according to data from the National Center for Education Statistics.