Hirayama (written: 平山) is a Japanese surname. Notable people with this surname include:
Aya Hirayama - an actress
Hideyuki Hirayama - a film director
Ikuo Hirayama - a painter
Kiyotsugu Hirayama, who discovered the Hirayama families of asteroids
Kōji Hirayama - a politician
Satoshi Hirayama - a Japanese-American baseball player
Shin Hirayama, the first Japanese astronomer to discover an asteroid
Sōta Hirayama - an international football (soccer) player
Tomonori Hirayama, football player
Yu Hirayama - a badminton player
Yuji Hirayama - a rock climber
Hirayama can also refer to:
1999 Hirayama - an asteroid
Hirayama (crater) - a luner crater
Hirayama family - a family of asteroids
Hirayama Station - a train station in Chiba Prefecture
Hirayama syndrome - a lower motor neuron disease