Ersa is a figure in Greek mythology.
Ersa may refer to:
- Ersa, Haute-Corse – a commune of the Haute-Corse department of France, on the island of Corsica
- Ersa (moon) - a small moon of Jupiter
- Ersa GmbH, a subsidiary of Kurtz Holding GmbH & Co. Beteiligungs KG for the manufacturing of equipment for electronic production.