The 1883 Casamicciola earthquake, also known as the Ischia earthquake occurred on 28 July at 20:25 local time on the island of Ischia in the Gulf of Naples in Italy. Although the earthquake had an estimated moment magnitude of 4.2–5.5, considered moderate in size, it caused intense ground shaking that was assigned XI (Extreme) on the Modified Mercalli intensity scale. Between 2,313 and 3,100 people lost their lives. The city also suffered great property losses, with 80 percent of all homes destroyed. This earthquake was exceptionally destructive for its magnitude mainly due to its shallow focal depth.

Ischia is a volcanic island in the Tyrrhenian Sea. It lies at the northern end of the Gulf of Naples, about 30 kilometres from the city of Naples. It is the largest of the Phlegrean Islands. Although inhabited since the Bronze Age, as a Greek emporium it was founded in the 8th or 9th century bCE, and known as Πιθηκοῦσαι, Pithekoūsai.