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 currently the smallest prefecture, by area, in Japan.
Kagawa is a relatively narrow prefecture between the mountains of Shikoku and the sea.
On September 26, 2005 the town of Shionoe from Kagawa District merged into the expanded city of Takamatsu.
On January 10, 2006 the towns of Mure and Aji from Kita District, the towns of Kagawa and Konan from Kagawa District and the town of Kokubunji from Ayauta District merged into the city of Takamatsu.