County Galway is located on the west coast of Ireland. It is in the Irish province of Connacht. The county takes its name from the city of Galway, which is the county's capital. It is the second largest county in Ireland, after County Cork. There are several strongly Irish-speaking areas in the west of the county.

Galway is the second largest county in Ireland and sits on the Atlantic coast in the west of Ireland with a natural indented coastline of harbours, deep fjords, and island clusters. The county is divided into two by the extensive Lough Corrib, Ireland's second largest lake, with fertile farmlands to the east and mountainous Connemara and boglands to the west. Off the coast of Connemara lies the island of Inishboffin, unspoiled and rich in archaeology and geology. To the south, in the mouth of Galway Bay, are the Irish speaking Aran Islands where age old traditions are found along side modern living.

The county comprises a number of distinct territories which predate the formation of the county by the English colonial administration in Ireland in the late 1500s. The major ones are Iar Connacht "West Connacht," which covers the portion of the county (and also a small part of County Mayo) west of Loch Corrib and which contains Connemara in the far west and Joyce Country in the north-west. The territory of Aidhne lies in the south of the county and is coextensive with the diocese of Kilmacduagh. The territory of Uí Mhaine or Tír Maine covers most of the east of the county but also covers south County Roscomman. Maigh Seola covers the portion of the county along the eastern side of Loch Corrib. A number of inhabited islands are administered by the county; they include Oileáin Árann (Aran Islands) and Inis Bó Fine (Inishbofin).

County Galway is home to Lough Corrib (the largest lake in the Republic of Ireland) the Na Beanna Beola (Twelve Bens) mountain range, Na Sléibhte Mhám Toirc (the Maum Turk mountains), and the low mountains of Sliabh Echtghe (Slieve Aughty).