The Awbeg River (Irish: An Abha Bheag, meaning "the small river") is a roughly 51-kilometer (32-mile) limestone-fed trout stream in north County Cork, Ireland, rising west of the Ballyhoura Mountains and flowing southeastward through Buttevant and Doneraile before joining the Munster Blackwater a few kilometers south of Castletownroche at Bridgetown Abbey. Widely regarded as one of the cleanest trout streams in Ireland, the Awbeg is primarily spring-fed on limestone, giving it consistently clear water and a stable, cool temperature year-round. The river drains a catchment of approximately 350 km² and flows through a mix of flat farmland north of Buttevant and a narrow, tree-lined valley with steep sides south of Buttevant. The riverbed is dominated by glides over gravel substrates, with a good mix of stream and pool throughout. Aquatic vegetation — including dropwort, pondweed, club-rush, watercress, and Ranunculus species — can become dense, particularly upstream of Doneraile during summer months. The fishing season runs from 15 February to 30 September.