Ballycumber (Irish: Béal Átha Chomair, meaning "ford-mouth of (the) confluence") is a village located where the R436 regional road crosses the River Brosna in County Offaly, Ireland. It is 5 km (3.1 mi) west of the town of Clara, on the western edge of Clara bog. According to the Census 2006, the district electoral division population for Ballycumber was 688 people. However, it is estimated that the population within the village boundary is approximately 260 people.
Ballycumber is located in the civil parish of Leamonaghan. The church in nearby Boher (dedicated to Saint Manchán of Lemanaghan, a local saint) was opened in 1861; before that there was a mud-walled church in the area which has left no trace.
The M6 motorway connecting Dublin and Galway is a ten-minute drive away. Bus Éireann runs an hourly schedule from Moate and Tullamore with buses going to Galway, Dublin, Waterford, and Belfast. Iarnód Éireann run a train from Dublin to Galway every half hour from Clara train station. Ballycumber station opened on 1 March 1862 and closed on 17 June 1963.