Galway is situated where the River Corrib meets Galway Bay and retains the essence of its medieval origins. Throughout history, this location has played a significant role as a crucial trading post along the western seaboard in medieval times, with its rich history revealed through archaeological excavations, showcasing structures like the de Burgo castle (built in 1232) and the Red Earl's Hall (constructed in the late 1200s or early 1300s).

The exact origin of the name 'Galway' from the Irish 'Gaillimh' remains unclear. However, one theory proposes that it may be related to the Galway (Gaillimh) River, now the River Corrib, and the Irish words 'gall' and 'amh,' signifying a 'stony river.' Local legend suggests that the town is named after Gaillimh or Galvia, the daughter of the mythical king Breasal, who is said to have drowned in the river.

Before the 12th century, Galway's historical records are limited. It emerged as a location where Toirdhealbhach Ó Conchobhair, the king of Connacht, constructed a timber fortification called Bun Gaillimhe ('the mouth of the River Galway'). The region around the present city was part of the territories governed by two local families loyal to Ó Conchobhair: the O'Flahertys to the west of the river and the O'Hallorans to the east.

During 1169-70, Anglo-Norman settlers arrived in Ireland, and in 1196, they laid their first claim on Connacht through a grant to William de Burgo. His son, Richard de Burgo, faced opposition from the Gaelic Irish at Galway in 1230 but returned in 1232 to construct the city's first stone castle. Richard's son, Walter, who passed away in the Galway castle in 1271, is credited with establishing the walled town, granting the citizens their first mural charter around 1270, enabling them to levy tolls on goods for financing the construction of town walls.