County Laois (liːʃ ; Contae Laoise) is a county in Ireland. It is part of the Eastern and Midland Region and in the province of Leinster. It was known as Queen's County from 1556 to 1922. The modern county takes its name from Loígis, a medieval kingdom. Historically, it has also been known as County Leix.
Laois County Council is the local authority for the county. At the 2022 census, the population of the county was 91,657, an increase of 56% since the 2002 census.
The first people in Laois were bands of hunters and gatherers who passed through the county about 8,500 years ago. They hunted in the forests that covered Laois and fished in its rivers, gathering nuts and berries to supplement their diets.
Next came Ireland's first farmers. These people of the Neolithic period (4000 to 2500 BC) cleared forests and planted crops. Their burial mounds remain in Clonaslee and Cuffsborough.
Starting around 2500 BC, the people of the Bronze Age lived in Laois. They produced weapons, tools, and golden objects. Visitors to the county can see a stone circle they left behind at Monamonry, as well as the remains of their hill forts at Clopook and Monelly. Skirk, near Borris-in-Ossory, has a Bronze Age standing stone and ring fort. The body of Cashel Man indicates that ritual killing took place around 2000 BC.
The next stage is known as the pre-Christian Celtic Iron Age. For the first time, iron appeared in Ireland, showing up in the weapons used by factions who fought bloody battles for control of the land. At Ballydavis, archaeologists have discovered ring barrows that date from this time period.
The county name derives from Loígis, of which the modern county is only a part. In the 11th century, its dynastic rulers adopted the surname Ua/Ó Mórdha. They claimed descent from a member of the Red Branch Knights.
By the first century AD, the western third of Laois was part of the Kingdom of Ossory. The eastern part was roughly divided into seven parts, which were ruled by the Seven Septs of Loígis: O'More (O'Moore), O'Lalor, O'Doran, O'Dowling, O'Devoy (O'Deevy), O'Kelly and McEvoy.