The Jerma () or Erma () is a river in southeastern Serbia and western Bulgaria. It is notable for passing the Bulgarian-Serbian border twice.
During the January 2021 floods, the Jerma flooded the road in its valley and overflooded the riverbed of the Nià ¡ava. This caused the spilling of the Nià ¡ava, which flooded parts of Bela Palanka.