Black rot may refer to:
- Black rot (carrot), a storage disease that renders carrot roots useless caused by Alternaria radicina.
- Black rot (brassica), an infection of Brassicaceae which begins as a yellow "V" shaped spot on edge of leaf caused by Xanthomonas campestris pv. campestris.
- Black rot also known as gummy stem blight, a fungal infection of Cucurbits caused by Phoma cucurbitacearum.