Jun-ichi Igusa was a Japanese mathematician who for over three decades was on the faculty at Johns Hopkins University. He is known for his contributions to algebraic geometry and number theory. The Igusa zeta-function, the Igusa quartic, Igusa subgroups, Igusa curves, and Igusa varieties are named after him.
He was an invited speaker for the 1962 International Congress of Mathematicians in Stockholm. He was awarded Japan's Order of the Sacred Treasure. In 2012 he became a fellow of the American Mathematical Society.