An earthquake registering Mw 5.1, the worst to hit the region for more than 50 years, struck near Lorca, Spain.

The 2011 Lorca earthquake was a moderate 5.1 M_w earthquake that occurred 6:47 p.m. CEST on 11 May 2011, near the town of Lorca, causing significant localized damage in the Region of Murcia, Spain, and panic among locals, and displacing many from their homes. The quake was preceded by a magnitude 4.4 foreshock at 17:05, that inflicted substantial damage to many older structures in the area, including the historical Espolón Tower of Lorca Castle, the Hermitage of San Clemente and the Convent of Virgen de Las Huertas. Three people were killed by a falling cornice. A total of nine deaths have been confirmed, while dozens are reported injured. The earthquake was the worst to hit the region since a 5.0 M_w tremor struck west of Albolote, Granada in 1956.

The moment magnitude scale is a measure of an earthquake's magnitude based on its seismic moment. M_w  was defined in a 1979 paper by Thomas C. Hanks and Hiroo Kanamori. Similar to the local magnitude/Richter scale (M_L ) defined by Charles Francis Richter in 1935, it uses a logarithmic scale; small earthquakes have approximately the same magnitudes on both scales. Despite the difference, news media often use the term "Richter scale" when referring to the moment magnitude scale.

Lorca is a municipality and city in the autonomous community of the Region of Murcia in south-eastern Spain, 58 kilometres (36 mi) southwest of the city of Murcia. The municipality had a population of 95,515 in 2020, up from the 2001 census total of 77,477. Lorca has the second largest surface area of municipalities in Spain, 1,675.21 km² (646.80 sq mi), after Cáceres. The city is home to Lorca Castle and to a Collegiate church dedicated to St. Patrick.