Uí Mháine, often Anglicised as Hy Many, was one of the oldest and largest kingdoms located in Connacht, Ireland. Its territory of approximately 1,000 square miles (2,600 km) encompassed all of what is now north, east and south County Galway, south and central County Roscommon, an area near County Clare, and at one stage had apparently subjugated land on the east bank of the Shannon, together with the parish of Lusmagh in Offaly.
There were two different Uí Mhaine, the Uí Mhaine of Tethbae and the Uí Mhaine of Connacht; these tribes were separated by the Shannon River. The people of the kingdom were descendants of Maine Mór, who won the territory by warfare. Its sub-kingdoms, also known as lordships, included – among others – Soghan, Corco Modhruadh, Delbhna Nuadat, Síol Anmchadha, and Máenmaige. These kingdoms were made up of offshoots of the Uí Mháine dynasty, or subject peoples of different backgrounds.