Bus Éireann is a state-owned bus and coach operator providing services throughout Ireland, with the exception of Dublin and the Greater Dublin Area, where bus services are provided by sister company Dublin Bus. It is a subsidiary of Córas Iompair Éireann (CIÉ). The company's primary hub is Busáras, Central Bus Station, located in Store Street, Central Dublin.

During the COVID-19 pandemic of 2020-2022 it was noted that Bus Éireann had been the only bus company to continue operating long-distance routes in the country. Speaking to the BBC, the general secretary of the National Bus and Rail Union (NBRU) Dermot O'Leary noted that as the majority of the Irish population stayed at home, the market for commercial companies to make profits on their normal routes ceased overnight, and they subsequently paused operations. As a result, "essential workers [reliant on public transport] could not have gone into hospitals, doctor's surgeries, pharmacies" were it not for Bus Éireann. Bus Éireann also provided the only bus connection between Athlone and the cities of Galway and Dublin for a period in 2020 when private companies such as Citylink temporarily suspended services.

The fleet consists of more than 1,200 buses and coaches. The company mainly uses buses built by firms such as Scania, VDL Berkhof and Volvo. Bus Éireann's fleet have been substantially invested in as part of the National Development Plan. The vast majority of the operating fleet for expressway, commuter, and local services are now five years old or less.