Saeki (佐伯郡 Saeki-gun?) was a district located in Hiroshima Prefecture, Japan.
As of 2003, the district had an estimated population of 54,592 and a density of 163.07 inhabitants per square kilometre (422.3/sq mi). The total area was 334.77 square kilometres (129.26 sq mi).
At the time of discontinuation of the district, there were two towns and no villages in the district.