Calomba is a rural locality in South Australia, situated in the Adelaide Plains Council. The formal boundaries were established in 1997 for the long established local name. The place name is supposed to have come from Trigonella suavissima, a native plant also known as calomba. It had a former railway siding, located between Mallala and Long Plains on the Adelaide-Port Augusta railway line. The area was formerly known as Shannon, but the railway station was named Calomba at its opening in 1916 due to the presence of another "Shannon" in the state.