Saitama Prefecture Miyoshi has a humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light to no snowfall.

The place name of "Miyoshin-no-sato" appears in the Heian period Ise Monogatari, and was part of ancient Musashi Province.

The village of Miyoshi was created within Iruma District, Saitama on April 1, 1889 with the establishment of the modern municipalities system.

Miyoshi has a mayor-council form of government with a directly elected mayor and a unicameral town council of 15 members.

In terms of national politics, the town is part of Saitama 8th district of the lower house of the Diet of Japan.