Towns and villages on Lough Derg include Portumna, Killaloe & Ballina, Dromineer, Terryglass, Mountshannon and Garrykennedy.

In the nineteenth century, Lough Derg was an important artery from the port at Limerick to Dublin through the canals in the midlands of Ireland.

Navigable over its full 38.6 km (24.0 mi) length, Lough Derg is today popular with cruisers and other pleasure craft, as well as sailing and fishing.

The University of Limerick has an activity centre by the lake, just north of Killaloe, where there are canoes, kayaks, windsurfing, sailing dingies, and other recreations.

[4] In June 2013, 35 people were brought to safety when a major rescue effort was undertaken after an international rowing event was hit by severe weather.