Portlaoise is fringed by the Slieve Bloom mountains to the west and north-west and the Great Heath of Maryborough to the east.

It was once known for the manufacture of iron and steel buildings, tennis balls, rubber seals, tyres, electrical cabling, and Ireland's first aircraft.

Today, Portlaoise is a commercial centre with the economy dominated by the service sector, and a hub of shopping, transport, and events for the surrounding catchment.

Its construction began in 1548 under the supervision of the then Lord Deputy Sir Edward Bellingham, in an attempt to secure English control of the county following the exile of Celtic chieftains the previous year.

The fort's location on rising ground, surrounded to the south and east by the natural defensive barricades of the River Triogue and an esker known locally as 'the Ridge', greatly added to its strategic importance.

The area had been a focus of the rebellion of Ruairí Óg Ó Mórdha, a local chieftain who had rebelled and had lost his lands, which the Crown wanted to be settled by reliable landowners.

This allowed the establishment of a Corporation of the Borough, a body which consisted of a burgomaster, two bailiffs, a town clerk, and a sergeant at arms, as well as various other officers, burgesses and freemen.

[5] The town forms part of the Portlaoise local electoral area and municipal district for elections to Laois County Council.

[7] Portlaoise Town Hall on Market Square, which was designed in the French Renaissance-style, was badly damaged in a fire in March 1945 and subsequently demolished.

[14] Due to rapid population growth and its location in the commuter belt, Portlaoise has seen the development of additional services, including a new fire station and a large swimming leisure complex.

[15] Portlaoise has a high percentage of people under the age of 15,[16] reflected in the recent construction of new secondary and primary schools.

State-owned companies Córas Iompair Éireann (railways, with a National Traincare Maintenance Depot in Portlaoise), the ESB (utilities, with a training centre in the town) and also An Post are all major employers.

Tourist sites near the area include the Rock of Dunamase (6 km to the east), a hill-top castle which dates from the 12th century.

Bus Éireann previously operated an intercity service between Dublin and Cork/Limerick which called at Portlaoise, though this was suspended indefinitely in 2020.

[citation needed] There is still one Bus Éireann service that stops in Portlaoise, route 73, which operates from Athlone to Waterford.

[citation needed] TFI local Link route 828 and 858, operated by JJ Kavanagh and Sons, serves Cashel and Thurles.

[23] Portlaoise's central location within Ireland and its concentration of restaurants, pubs, bars and nightclubs around Market Square, Main Street and the Church Street area of the town centre and other nearby facilities such as paintball, golf, bowling and other amenities make it a popular destination for hen and stag parties and other weekend breaks.

It has featured large scarecrows including King Kong, Pope Francis, Noah's Ark and Electric Picnic.

The town is dotted with scarecrows made by local groups, children, businesses and people from neighbouring counties.

These include courses and professional certification in beauty therapy, hairdressing, healthcare, nursing, business studies, information technology, and sports and leisure management.