Mihara-ku (美原区?) is a ward of the city of Sakai in Osaka Prefecture, Japan. The ward has an area of 13.24 km² and a population of 39,230. The population density is 2,960 per square kilometer.
The wards of Sakai were established when Sakai became a city designated by government ordinance on April 1, 2006.
This ward includes the former town of Mihara, which joined Sakai by merger on February 1, 2005.
Coordinates: 34°32′18.77″N 135°33′35.39″E / 34.5385472°N 135.5598306°E