Kagawa is bordered by the Inland Sea and by Ehime and Tokushima Prefectures.
Kagawa comprises the northeast corner of Shikoku, bordering Ehime Prefecture on the west and Tokushima Prefecture on the south, with a coastline on the Seto Inland Sea facing Okayama Prefecture and the Kansai.
Kagawa is a relatively narrow prefecture between the mountains of Shikoku and the sea.