Hiraoka (written: 平岡) is a Japanese surname. Notable people with the surname include:
Hiraoka Fusazane (平岡 房実, 1513–1572), Japanese samurai
Hideo Hiraoka (平岡 秀夫, born 1954), Japanese politician
Hideo Hiraoka (racing driver) (平岡 英郎, born 1971), Japanese drifting driver
Hiroaki Hiraoka (平岡 拓晃, born 1985), Japanese judoka
Hiroaki Hiraoka (footballer) (平岡 宏章, born 1969), Japanese footballer
Hiraoka Kimitake (平岡 公威, 1925–1970), Japanese writer, poet, playwright, actor and film director, better known as Yukio Mishima
Naoki Hiraoka (平岡 直起, born 1973), Japanese footballer and manager
Takashi Hiraoka (平岡 敬, born 1927), Japanese mayor
Taku Hiraoka (平岡 卓, born 1995), Japanese snowboarder
Yasuhiro Hiraoka (平岡 康裕, born 1986), Japanese footballer
Yasunari Hiraoka (平岡 靖成, born 1972), Japanese footballer
Yūta Hiraoka (平岡 祐太, born 1984), Japanese actor
