The Miyazuka Kofun (宮塚古墳) is a Kofun period burial mound located in the Hirose neighborhood of what is now the city of Kumagaya, Saitama Prefecture in the Kantō region of Japan.

[1] The Miyazuka Kofun is located on a river terrace in the middle reaches of the Arakawa River, and is part of the Hirose tumulus cluster, which has many densely packed small-scale tumuli.

It was built in the latter half of the 7th century, or towards the final stages of the Kofun period.

It has never been excavated, so the structure of the burial chamber or presence of any grave goods is unknown.

Although the base was originally square, it has been partially cut away by local farmers.