Hiroaki Terao (寺尾 宏明, Hiroaki Terao, born August 13, 1951) is a Japanese mathematician, known as, with Peter Orlik and Louis Solomon, a pioneer of the theory of arrangements of hyperplanes.
He was awarded a Mathematical Society of Japan Algebra Prize in 2010.
For his graduate studies he went to Kyoto University, where he earned in 1981 his Ph.D. degree, with a thesis written under the supervision of Kyoji Saito.
He is currently a guest professor at Tokyo Metropolitan University.
In 1983, Terao asked whether the freeness of an arrangement is determined from its intersection lattice.