A prefecture located in the Kantou Region of Japan on the main island of Honshuu which borders Tokyo. It was formerly part of the ancient province of Musashi, which was the largest province in the Kantou and also produced much of the food that fed the region. Its capital is the city of Saitama.

The prefecture is part of the Greater Tokyo Area, and a large number of its residents commute to Tokyo each day from Saitama's cities, which can be described as suburbs of Tokyo.